ConcoursMustang Forums
Restoring - General discussions that span across many different groups of years and models => Body, Paint & Sealers => Topic started by: Bossbill on December 29, 2017, 02:23:41 PM
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Somewhere I saw an article on how to replicate undercarriage floor paint drips using a hypodermic with a small sponge around the tip, sans needle, of course.
Maybe it was here -- maybe somewhere else.
I can't find it -- any help appreciated.
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I recall at least one discussing the "faking" of the runs and drips on the undercarriage and the few pictures that accompanied the thread. Like you it may have been on another site but the search over there didn't turn anything up. If we discover it later we can always merge the two but its important enough to go over it again since there is a need.
Think Brent's posts of Jeremy's restoration of one of those cars may be the thread (linked) that we both may have been thinking of from a couple of years ago
I've not had to do it before (just went the "lots of paint route") but recall guys using rattle cans to focus on the low points, building the paint until it pooled and gathered then finally forming multiple drips as planned. There are allot of these points so its going to take some time. A bunch of drips in one area while none in others is only going to look odd, inconsistent and unoriginal IMHO Also the body is going to need to be level and upside down.
The thin rattle cans will provide a very narrow pattern and you may need to come back and feather the edges away from the ribs once everything is dry so that the process is not obvious
Sure some others will have some additional experiences and thoughts to share
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A bunch of drips in one area while none in others is only going to look odd, inconsistent and unoriginal IMHO Also the body is going to need to be level and upside down.
Drips were not a desired characteristic. They occurred on the raised (downward) parts of the floor pan and mostly to the rear (caused by gravity and forced air drying?). There were a lot visible on the right side and very few on the left at the rear of the pan just before the upturn for the rear axle. They were all very solid, as in many years of drying. This was on a San Jose March 66 build.
Jim
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I should add that the 67-68 MCA judging guide states on 5A "primer paint drips should be visible . . . "
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I should add that the 67-68 MCA judging guide states on 5A "primer paint drips should be visible . . . "
Don't think that is important for the discussion ;) It's IMHO more about what was original and how to replicate it.
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Would it be hard to color match the "drip paint" to the underneath color? Like Jeff said, I and have done, wouldn't be easier to just repaint with a higher volume to make things equal? If you are going this far, the drips should have body color over spray on the outside of the drips. I did manage to get this on my car. But that be really anal. If your going to do it, try hard to do it right.
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Muscle Car Restorations in Chippewa Falls, Wisconsin was restoring a B9 (http://www.hotrod.com/articles/boss-of-the-barn-restoring-a-barn-find-boss-429-part-2-undercarriage-restoration/).
The primer/sealer floor drips looked just like the 67s. They explained that the drips weren't so much drips as "drips that exploded after going through the baking process."
That actually made a lot of sense since a lot of the drips I've seen actually look like craters, rather than drips. What I've been trying to replicate is this moon crater look.
This is the first I've heard of baking the red oxide, but it makes a lot of sense since it's impossible to assemble a car with a wet primer underbody.
Was the floorpan baked at the factory?
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For 67 San Jose I'm not convinced that they are popped bubbles or collapsed drips or bubbles. Also not sure how air or fumes could have been produced inside a drip while not producing the same results in runs right next to these things. The reaction of the drips might be a result of exposure to heating lamps where the outer surface dried first then still not completely dry collapsed upward or the body was rolled causing this. IMHO knowing why isn't as important to us as how to reproduce the look on our restored cars though we do continue to try and find out how the process was done when possible.
Looking at San Jose examples I would report that maybe 40% of the drips produced these divots and in those cases 80-90% collapsed rather than what appears to be bursts shown on the 69 Dearborn example you have in the link. When they collapsed they didn't leave bare metal showing but sealed back up leaving often an odd multi-legged (for lack of a better term) pattern in the collapsed drip.
A few 67 San Jose examples - It should be noted that not all cars had as many drips or at the same location the pictures are provided only for discussion of the subject at hand
Passenger side front frame rail and outer floor pan
(http://www.concoursmustang.com/forum/gallery/9/6-301217010044.jpeg)
Typical drips collecting along the low points of the floor pan. In this example the ribs just behind a front seat
(http://www.concoursmustang.com/forum/gallery/9/6-301217005955.jpeg)
The rear floor under the rear seat riser. In this case the ribs are formed upward so the paint collected on the main floor surface here as well as runs on the seat riser panel since it is not perfectly flat
(http://www.concoursmustang.com/forum/gallery/9/6-301217010024.jpeg)
To the far right in the following picture you can see the runs that collected as the rear (under rear seat) flowed into the main floor section
(http://www.concoursmustang.com/forum/gallery/9/6-301217010012.jpeg)
Hope this helps.
And I haven't forgotten about your fastback trap door questions ;)
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It's always a losing game trying to explain one year's/one plant's methods to another's, isn't it?
I think it's solvent pop. The gif below explains.
Thanks again for the pics. I hope it helps others as well.
Back into the shop to experiment on spare sheet metal.
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...I think it's solvent pop...
No, definitely not solvent pop. Solvent pop appears more like small pimples.
Chris
(http://www.concoursmustang.com/forum/gallery/9/2850-301217100136.jpeg)
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Hmmm...
This discussion is of huge interest to me. I have about 30-50% (maybe more) of the original drips and many are popped yet many are not. I also think a good number of the lower portions of the underbody, were scraped off in an accident I had when I landed the car really hard in the open deserts of the Mojave once...front frame rails were wiped clean (for instance) and some of the lower ribs were also wiped clean of the drips. I wouldn't mind putting back what would be typical.
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- the drips weren't so much drips as "drips that exploded after going through the baking process."
That actually made a lot of sense since a lot of the drips I've seen actually look like craters, rather than drips.
Yes it does.
The undercarriage pictures are from a 66 GT Fastback I sold in 2005 (San Jose March 28 - sched). With the car on jack stands, I spent some time on my back cleaning. I made no attempt to remove any drips.
Jim
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No, definitely not solvent pop. Solvent pop appears more like small pimples.
Chris
I agree that all of the recent paint threads seem to indicate that solvent pop is usually very small.
But finish paint is not slathered on with giant nozzles and baked on to speed drying while the car is moving (I think).
Plus, the car primer/sealer application is upside down and the paint is already dripping off.
I have no idea how long the bake cycle was on the underside (or even the top) but it had to be fairly hot to get the primer to dry in the mere minutes allowed.
So if it isn't solvent pop, then it's something else in the paint reacting to the heat and exploding. The other thing it could be is water. The later seems a bit unlikely. It could just be the extreme temperature to which the dripping paint is exposed. Which brings me back to the most volatile agent in the paint coming out quickly.
I'm open to suggestions as to how to replicate this effect regardless of how it was initially created.
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Seems like Virgina mustang, maple hill reproduced it in a recent Shelby.
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Seems like Virgina mustang, maple hill reproduced it in a recent Shelby.
They may have just sprayed over the original surface (if its the car I'm thinking of) since it was doable on that car.
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I'm open to suggestions as to how to replicate this effect regardless of how it was initially created.
Since we're just bench racing the idea lets me offer a couple of possibilities to start with and we can work though the good and bad points of each.
1- Do a base coat of primer to build up the product while the car is upright along one panel region to keep control and not let drying get ahead of us if we tried to do to large an area at one time. Once the drips are set but not hard choice a random number to squish (if possible roll the car upside down) Given the size of the possible drips you would choose (the larger ones) you might use a wet pencil eraser since it has rounded edges and is approximately an acceptable size. Might even experiment with cutting a pattern in the tip to produce those lines we see
Finish by feathering in the edges of the primer you used for the process
2- Do the same process with just the floor color over the whole floor and frame (firewall rear ward or firewall forward) and depress a percentage of the drips. Problem I see with this methods is that the perfect time to do this will be very narrow and there is allot of area to cover but if you only do a couple dozen it might work.
Just some quick thoughts to get the discussion going. Wish I had the time to test out the possibilities on some of the floor panels laying around
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Here is the car
http://blog.virginiaclassicmustang.com/search?q=Drips
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Here is the car
http://blog.virginiaclassicmustang.com/search?q=Drips
Different car but that is the pictures I think Bill and I were thinking of in the first couple of posts. Thanks
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I talked with people that worked at the Lorain Ohio plant that built my Cyclone, (Yes, from 1969). There was a guy in a pit that had to paint overhead to paint the bottoms of the cars and they had larger, more volume guns than we use to paint our cars. I used a 2 qt pressure pot to paint the bottom color on my Cyclone, that gun really puts out the paint and did a good job of runs and drips. Isn't just as simple as the drip drying out and shrinking back that causes the drip to look like that. From the vintage videos I have seen, the paint guns used in the auto industry are much higher volume than we have, the pattern is just huge. 3 passes and a panel is done. No HVLP gun I have used has that large of a pattern, nor would I want to. The learning curve on no runs might be tough.
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Thanks for the suggestions.
The Virginia Mustang car has the right flavor of pops, but a bit milder than some of the moon craters in other pics. But, perfectly satisfactory.
I've seen the videos of the painters slathering paint on -- that's an amazing amount of paint volume. I'll bet the undercar paint jets had some volume too.
I talked with my painter earlier this morning and he suggested about what Virginia did -- thinned epoxy primer -- but thought some localized heat might help. I'll try a few of these ideas in small scale and let you see some results in a few days.
If I could ever shake this lousy winter cold I might be able to get something done, so don't wait up.
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I recall hearing from Adam at Mascar, that he would spray the underside with water before painting it in order to get drips that looked right.
I don't know if he had a layer of paint on it already, and then wet it and resprayed some more paint, or how exactly he did it. But maybe you guys with experience will understand how that might work?
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It's been slow going with some sore back issues.
But I had a chance to red oxide a spare rear floor section and then begin some experimenting.
I haven't had time for the drips to fully harden yet and recoat with red oxide, so here they are without a recoat.
I've used different tools and processes to create this variety -- yes, some are failures -- and thought I'd post to gather opinions before I either paint or build up some more.
Although I have a rotisserie, I decided to make the "drips" while the car sat normally. So I situated the spare rear floor panel above my head in order replicate how I will eventually do this.
The three numbers represent three different tools to make the dots.
The horizontal line represents no heat applied above the line, and a pinpoint butane torch applied to the dots to make them explode below the line.
(http://www.concoursmustang.com/forum/gallery/9/4249-090118190812.jpeg)
(http://www.concoursmustang.com/forum/gallery/9/4249-090118190812.jpeg)
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Sorry, I just saw this thread.
The drips made on 6S033 were duplicated by Jeremy at Maple Hill Restoration. It's been something that he has been messing with for a while. We were always afraid that the drips may remain "soft", but they turned out to be very hard and durable, just like you see with the original ones.
The epoxy primer was just thinned down and sprayed at the right consistency to work. The drips/bubbles just kind of collapsed, and we were really pleased with the way it turned out.
The top coat colors were then put on and the correct "look" was still there.
Here are a few pictures:
(https://lh3.googleusercontent.com/Jna8QyC3BwRNqRuFniIdnJ2m7qvOvL5Tw_xzXRs32KD_jg055iIW9Cr3wbYFiITRMcM3mk0cBcISbt0hylXkR4-OIN9h33KGtvsmnEPo1KUm9Hj3sTXwMyxuzcXAIc-MiKeZyVMTL5aJlszcY_LkZSQ-_aSZWHSOHefsGTOTZKLZaWkbZakE_8iEq4xzw6GgDUmOxPoJO_wq7TwYCW8Oxx5-PlKP2NurPt08Bxoi8Zthu3PnziOxl8efKbsRa1UUjBOLrebuiH8ZohBjrLIa7bAqO7sj24gIge2qpF7lShvU58elEaKjw4X9IudbipfVmeJNdvcmgjSSalHq3vEvLxB2L41LvTDmSl8OCUxwbFIW-lvjqmyi6uUUu_l3MhVzCgnI1r82wThtrFaTsh7ebJ9Xmz8KivSFtUTVZ5HSerUQmVRccgMTRONfqpVtfEObpseTeoEN-9UmQ3Gv2XIvhY3P2tGKs0vZAWaZxDwlYXjAijdgdGBg5KshkC7PFXuSdiz0vOMaCn1TCv6-cOwVRKvT-gcsfJOdajjOlVV_RGuzi9c33zVLbJHchLW6a-XS5Stg2WWgMwaRGiS2HOBdI9GlWYpbdcpKs3qYidVR=w600-tmp.jpg)
(https://lh3.googleusercontent.com/e-mxDwSqz7Qheig3hQuCQUnD9KEgsKyOzMdYCgdvE_yNv6ObalZpH_eCRZ4_YGlxP7rP1OF4zwM9MsifftXtvv5k2M8ycS0AuVwZStNFCwoLo1NpY0RhsObEi87pJkie2xGVcpfnj_TmbalGEhZK87z26GOMRBYAZGgLohMwrIq7vvAieQMpdg-dB4L0bFo0OLBMYDmsqzFmQ89MPvlnmSL5YGwho-Tk0p7PIul_TDFDh83ipi47K4IZfrV-88QKfRuosPf3Ln0kYUMUKTGRF6pg2q7tB1TSpC0LHvZAu5dvfm3rqYiWLDHXFRuMj2_laCUmoEtjN7fiLEQuC09SEMGcmYs9BojRc9s-j76ugutfs2AaP5m-MGZ69UZP4ezuIh23IhEdyBPyXPZC-KUIPR94GXKL3N_q03ULtNpat9Vt2kzlmaopiP-gyoE31zvdZxCpu3bcZrTmt1TpDLMi2eGRVzctB8_Gj_QJJ0xo56HzPQLysRfERZRL_pTCpCD0F3QyH0HwOgOtywiH3ppXtRXS-GLIEpt0Yz-Z2nEzEeLpTt90eHyNAF5KBUVlzQPdnVFHg5yF_1cQ4YystrJaiRtigE_um_mOwT80EybM=w600-tmp.jpg)
(https://lh3.googleusercontent.com/CK4mi-IXbOzpJa1KJjRlRVurAZFNDz6-gHxxU3SjXoBrt8zglLawPq5Ju9ubz4YmEhUT_7XCrotvHwvye3IhPvZ-zw33a3u1J4FUDW98Azxm2p-8EpmOuPcvps32Lu0zVsVjwibyYm4cbJEvEBc6AOm8CM1TUCVzeVw02SnaVnoRGYrSDDMo2MIms9tB_Pi5MUZSkIeuQ3i9aqj1sesgsagZyd32nlo8Ri8Z_PKSKI-JJWi7pMM0JJDJnuOY2fXZ05L51a6YreJdwd_Bo-0eVuo1KBsZEQJeUyNTes_TLZZJ_hUtO4hTsAjnMTkxcBs4LILm3nBjV-ZUKkR5hmko8oBbTNdEjqCr54k1IMmSQkAIX7TPtxzI6Vpj78RU-TwVM_l7aQoJrv7Gobr07Vi-9LSeB4RJpqTkiswKSO0ps3RotVC8Nmel9_GBGuLDpEUy_WnlR7-_mMJTcaPIwVGykOXRhn1bLG_Y1ZK2ksbjNDklI9JRnDBiQSvmVCrvqS8UAdAW3OZmNZjAVIUtSulrFYqp9AwA8TPBO8T3jYKlOvZJV7GJGbKO57GQXsb7AnFwMtsgGyO58szp-mCt5eGuKtK0Lvdr8-itq72F0bJx=w600-tmp.jpg)
(https://lh3.googleusercontent.com/R2iO5hJ7B0V--pNoCA3C3fWc5C2pQPIp57Cgr5W2CkX63ZhMaldWLTNqHwO1uXrZlcnjdc1UKmCtkIrSGnHj0lXV_o16iAa9p5WpkKA-3CA8dNy5hAvb6SeHsmFycH-CGXApIEJWE8IqSn-DRBK8qX1BIyOZkLYtdjL17tg094eiVA3LJvbKei6a10M7Fj2wmuJMdSUMHM5ggLEpU_DbPra7PmTHDBGLq3hnLrKoeI0TKDNNmOQzVLY1wqZn7sc2ghvb8ptQQsFRoyngj637HE5zPP5Jrlaz1ZUXHvlOuPnX-ePs840a-exsvpPOJTkjNF-7od_65A9kn4l0V7NFq5C-KqwJbSOh8wn2iZ3gGWv84dG_Huw9Mcqg5NQSSCzX7GRu5aO8MMUZrGyFaY0qU3xYRVpTT_dnp7y4AeUH5TPnNpF_DsBL0aCBM_oetRtLv_ewNGt7xUXtLgMkCCcKDKoYebj7cw4rEbh4-kxdPs-4yr-lPBqIc3hi3qd7zDb22mWzkjNWpaWx0EJGILfrySzyqjsad26_2xZegYv1mq2tvO0fMW6dpwDPOyXkmkJsBG5sxR7DYyd3JnbI41FqDb6qKgKE2Qbc8Z9IRvzm=w600-tmp.jpg)
(https://lh3.googleusercontent.com/WPw2uJeokwnK-AtoSW_Wk3qvw96rI4J7bvQypoZLXufKkSQlsZXzx57XJ1beULz5MrCbXfeubQQgg9YaJfSCSHee0ZZv9UgC2xF2sf6fR2iIaN_eRvBrVPONlB89E3NFGQ1ld7hUZfP_msSGgsog7LVOP6wZoyoHymew6I5PwSMaXwbq_x6_4ovc7DiYu2nCu4swVtCgXzZu392kXYX1xELoZyv5PUI-flfUqQoWdq64jhbmnCZryyHT1sh3fnlKy3g2awZVRu0Hl8HnQkRPXGOkyzdSbWXNejk9_mi7YsqqXZbjD5jSB2xhAEQwSygBaHi0q4l1wxeBIqlS7VQ0VFfBXy2j8DY1ZYsYCH1jo9aCz_3wmV73ErJp3Bb-gaNoqAm5QsfkmqB4VjLPAU9_TVMd0C40qnVjD3Z8d4_kLZeve7rsSpeJad2cI-aI5oCQmXQgqAyHZW2ZChYwARzkzSS-sk2uBBk-5rc-oAOLEne-eQwIYYhQN8ONXwHOXGR9KE1FlVrm7x5hS1un_5RrHwj-vqP1YCHK3qIbcheLoLVa2kdNX7FZIFd2QFMr6b3symOksZ6I9enG0XtHiUVRbJND5Rb6jK7vQ7rKUFo4AtCW6qdLpPsdimaOwjp6lRWD49pVLO-MdZvB0pvzqUkgSu51okwd-vowuQ=w600-tmp.jpg)
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After having spent hours and hours on different processes and techniques, I think I have a method for creating faux drips. The best part is that I can choose where they go, and I can emulate the many different types of drips. I even have a process for the round circle drips!
It does rely on the car being on a rotisserie as the floor needs to face up. This process works best using gravity. I didn't want to spend even more time experimenting with more and more primer reduction on the real car -- and getting it wrong. I need to move on and this process should work for me.
Here is a pic where I used brown gloss paint to show the 'drips' as I didn't want to mix up DP. Ignore the lower left drip -- this was a test.
I think I'm on the right track ...
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Rotisserie assembled, car lifted and flipped.
Let the faux drip process begin!
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You Guys Crack Me Up ;D
The factories got these drips as a waste product of their paint process. They achieved it unintentionally and it was created by unskilled, entry-level undercarriage spray people who were even using "slop reclaimed paint" in some cases. Because they were painting a generally unseen part of the car, their work was most likely not even inspected by QA.
The most logical and easiest way to achieve factory-authentic results is to try and copy what was done at the plant. The variables you will need to control are viscosity, temperature, volume deposited, smoothness of unpainted substrate, and rate of deposit. Their guns probably sprayed near a gallon per minute. Once the paint is in the belly and drips have formed, a large bed of heating element coils like a vacu-forming machine uses needs to be positioned about 12" beneath the floor and turned on to cure the floor at about 180-220 DegF. This will boil the trapped solvent in the drips and make them POP like when cooking pancakes. Smaller bubbles will pop differently than larger ones. They will look different. Really small bubbles will simply dry and harden without popping.
It won't be easy but it will be easier than "faking" them and getting an appearance that is less than optimum. Once one person has success, their method will catch on like wild fire. :)
(http://www.nova-labs.org/blog/wp-content/uploads/2016/04/IMG_5969.jpg)
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I think everyone agrees this process involved fixed spray jets that hosed the primer on as the car went forward on a trolley.
After many hours of testing various paint mixes (a tremendous amount of reducer/solvent) I understand how much to put in the primer. I could also use a pressure pot and really slather this stuff on with the pot hooked up to my old Binks.
But I'm not interested in taping off that much of the shop in which I have the hoist. I'm also not interested in creating an oven under the car. Especially with all that solvent floating around.
I can paint my faux drips with a detail gun, not a sewer hose!
Like the wheel well undercoating process Jeff has created, which involves no tar based stuff of any kind, we are trying to duplicate what it looks like, not necessarily the way it was really done.
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+1 on fixed spray jets. They usually started with a line directly vertical from the edge of the firewall. The idea being so paint wouldn't be wasted by blowing up through the engine bay. The front frame rails from that edge forward were normally done by hand, so we don't see the same type of drips as the belly of the car.
This level of detail is what separates good restorations from great restorations!
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Hey Bryan... with a little patience, I believe the same forced heat method can be achieved with either large heat lamps or with a heat gun. I like that mention of the bubbles popping. Brant's car is a great example of the correct look.
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I think everyone agrees this process involved fixed spray jets that hosed the primer on as the car went forward on a trolley.
+2 :) This is backed up with examples where jets apparently plugged up and left a strip of bare steel for a section of floor. Those bare sections are often very straight - something we would not expect or find if the car had been done by hand front he firewall rearward. We also have some examples were the jets (all fo them ) just stopped at one point across the whole undercarriage suggesting the some one hit or struck the leaver that made contact with the dolly/trolley at that point shutting the jets off. In those cases the section of bare floor was corrected/fixed by hand
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I thought the complete car went through a submersion tank of primer like the old videos showed or were they just water washing tanks?
Daven
9R02R107xxx
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I thought the complete car went through a submersion tank of primer like the old videos showed or were they just water washing tanks?
Not Mustangs. Have heard some of the 'higher' end cars went through that type of process, like T-birds.
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Oh, that explains why the cars I saw were full bodied. Are the old mustangs considered the highest valued, or high end cars now?
Daven
9R02R107xxx
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Oh, that explains why the cars I saw were full bodied. Are the old mustangs considered the highest valued, or high end cars now?
Most likely, depending on the model/options.
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Not Mustangs. Have heard some of the 'higher' end cars went through that type of process, like T-birds.
+1 Mustangs were treated much like Falcons that they were based on (unibody design)
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It's too cold to go to the shop today. Without drowning you guys in a bunch of detail ...
The May 1964 New Scientist explains that "the end of 1961 saw Dearborn using electro-coat painting for motor car wheels, with 4-5 million wheels painted by May of '64."
Before 1963 [exact date not mentioned] Ford was using "slipper dip" for primering the lower half of car bodies for Lincoln and Thunderbird.
In October 1963 Ford's Halewood factory starting electro-coating these two car lines using 70,000 gallon vats of primer.
Cost and the availability of these vats in the many Mustang factories may have precluded their use.
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Not sure if the earlier reports apply during the periods when Mustangs were produced. For examples the complete bodies of the other cars were dipped not just part of the bodies
Cost and the availability of these vats in the many Mustang factories may have precluded their use.
At least at most of the plants were Mustangs were produced the vats were in use on other lines within the same factory. Though I do agree that it was a cost saving item for these cheaper built cars to keep the prices down and the cars affordable/price competitive.
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NOTE: The following six posted were split and moved from another thread in an effort to keep related discussions, findings and help all together for others to find and consider
Finally had good enough weather to "do" my paint drips.
You be the judge ...
(http://www.concoursmustang.com/forum/gallery/10/4249-260418180852.jpeg)
(http://www.concoursmustang.com/forum/gallery/10/4249-260418180812.jpeg)
Great work Bill how did you emulate the paint drips
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Get ready to experiment!
I tried painting some spare floor panels in order to get the drips. I had some success but if you get the formula just a little wrong you end with a mess that requires a lot of sanding, more primering and a possible loss of detail. So I decided to create the drips by hand and where I wanted them. See the Virginia Mustang Blog for their paint results.
I started with a product Jeff recommended for wheel well and other sealer use, called Spectrum. Check the library as Jeff has an article on that use.
It's sold by Second Skin Audio for use as a sound deadener. The Spectrum product is sold as a spray on product called either "Spray on Deadener".
"Sludge" is the same thing as the "Spray on Deadener", but includes a bottle of a thickener. You want Sludge.
The thickener just raises the viscosity from a light pancake batter to cold butter or anywhere in between by adding more or less of the thickener. The thickener does not reduce dry time so it is not a catalyst. It's more like adding flour to a recipe.
Check pictures of SJ car bottoms (like Richard's) to get a sense of the pattern of drips. Print out the pics of sections you want to emulate.
The factory drips are a result of the body being moved over a row of paint jets, pointed up, as the body moves over them. The application is heavy enough to cause drips. The body immediately moves over a bank of heating elements. I'll leave the type of heating elements out of this discussion.
The heating of the still dripping paint caused some small drips to instantly harden. Some drips were larger and stayed intact that way. Others exploded due to "solvent popping" and looked like a post eruption volcano. Some exploded so much they ended up looking like moon craters with just a ring left over.
Basically there are three drip types. Small dot drips, large drips and exploding drips.
A fourth drip is not really a drip but a crater.
To prepare, experiment with the spectrum and a few drops of thickener. Use either a hypodermic without the needle or a pet medicine hypo. The later is used to feet cats and dogs specific amounts of medicine and has hole on the end well suited to this task.
I use one hypo for adding thickener and another to dispense the sludge.
Using a rotisserie, flip the car upside down.
Small drips are just that. Experiment with viscosity in a small container and just lightly apply to a rib with the hypo. Since this stuff is water soluble you can quickly remove it. I used a spare floor section for the experimentation phase.
Larger drips are usually just more thickener and more product.
Exploding drips require a timer. Make a large drip, let it dry some amount of time, poke the middle and let it sit. It should look "exploded".
The craters are done using a circular item like a ball point pen middle section (where they are screwed together) or a hole punch. Dip the open end into the sludge and apply to the floor. This might either be straight down or using a rocking motion.
Some drips make take more than one application.
After you have enough drips I take the base of each drip apply a little 2k primer to where the drip attaches to the floor so as to smooth out the transition.
Finally I apply as many coats of 2k primer to the floor to even it all out.
This requires a lot of experimentation to get the results you find satisfactory. If don't have a lot of patience this may not be for you.
As a final note, sludge can be mixed and placed into plastic baker's bags for the rear trunk areas that used to have the tar-type sealers. You can use tools on sludge to move it around or to create patterns like stacked dimes.
Included are pics of various experiments and final application (yellow glove).
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Almost responded to bullitt68's request (answered for you) but choose to let you do it and glad I did. :)
Really nice explanation and write up.
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Get ready to experiment!
I tried painting some spare floor panels in order to get the drips. I had some success but if you get the formula just a little wrong you end with a mess that requires a lot of sanding, more primering and a possible loss of detail. So I decided to create the drips by hand and where I wanted them. See the Virginia Mustang Blog for their paint results.
I started with a product Jeff recommended for wheel well and other sealer use, called Spectrum. Check the library as Jeff has an article on that use.
It's sold by Second Skin Audio for use as a sound deadener. The Spectrum product is sold as a spray on product called either "Spray on Deadener".
"Sludge" is the same thing as the "Spray on Deadener", but includes a bottle of a thickener. You want Sludge.
The thickener just raises the viscosity from a light pancake batter to cold butter or anywhere in between by adding more or less of the thickener. The thickener does not reduce dry time so it is not a catalyst. It's more like adding flour to a recipe.
Check pictures of SJ car bottoms (like Richard's) to get a sense of the pattern of drips. Print out the pics of sections you want to emulate.
The factory drips are a result of the body being moved over a row of paint jets, pointed up, as the body moves over them. The application is heavy enough to cause drips. The body immediately moves over a bank of heating elements. I'll leave the type of heating elements out of this discussion.
The heating of the still dripping paint caused some small drips to instantly harden. Some drips were larger and stayed intact that way. Others exploded due to "solvent popping" and looked like a post eruption volcano. Some exploded so much they ended up looking like moon craters with just a ring left over.
Basically there are three drip types. Small dot drips, large drips and exploding drips.
A fourth drip is not really a drip but a crater.
To prepare, experiment with the spectrum and a few drops of thickener. Use either a hypodermic without the needle or a pet medicine hypo. The later is used to feet cats and dogs specific amounts of medicine and has hole on the end well suited to this task.
I use one hypo for adding thickener and another to dispense the sludge.
Using a rotisserie, flip the car upside down.
Small drips are just that. Experiment with viscosity in a small container and just lightly apply to a rib with the hypo. Since this stuff is water soluble you can quickly remove it. I used a spare floor section for the experimentation phase.
Larger drips are usually just more thickener and more product.
Exploding drips require a timer. Make a large drip, let it dry some amount of time, poke the middle and let it sit. It should look "exploded".
The craters are done using a circular item like a ball point pen middle section (where they are screwed together) or a hole punch. Dip the open end into the sludge and apply to the floor. This might either be straight down or using a rocking motion.
Some drips make take more than one application.
After you have enough drips I take the base of each drip apply a little 2k primer to where the drip attaches to the floor so as to smooth out the transition.
Finally I apply as many coats of 2k primer to the floor to even it all out.
This requires a lot of experimentation to get the results you find satisfactory. If don't have a lot of patience this may not be for you.
As a final note, sludge can be mixed and placed into plastic baker's bags for the rear trunk areas that used to have the tar-type sealers. You can use tools on sludge to move it around or to create patterns like stacked dimes.
Included are pics of various experiments and final application (yellow glove).
Thanks Bill all of then information you and others are providing is invaluable. Now I just need to try my best to see if I can do the instructions justice. I was going to leave the paint drips on my car as a lot of them remained after media blasting but decided to remove them before painting as the caps of the drips were removed and the remaining creaters would just not have looked right. Looking forward to experimenting with your procedures. I am going to start updating my build thread as I go and post the results if they turn out well.
Here is what my drips looked like after blasting and a photo of the drips before blasting and then a photo of the car painted with no drips. It is amazing how the some of the drips were really bonded to the metal and did not come off with the media blasting. Fortunately I have great photos of all of the drips on the bottom of my car. I have not seen may photos of other cars, but the drips do seem tone minimal on my car and will try to reproduces them as best I can. The down side is that I never put my car on a rotisserie and did all of the work so far on just a body cart. Do yo think that this process/procedure can work on the c art or just be harder as it will be done in a tight space under the car. I am not kicking myself for not putting the car on a rotisserie
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............... Do yo think that this process/procedure can work on the c art or just be harder as it will be done in a tight space under the car. I am not kicking myself for not putting the car on a rotisserie
Of course you can do it. Many have done it before. Just not as easy and for this task (where the floor needs to just sit as is usually does for the drips and epoxy top coat) a rotisserie isn't needed since you don't need to rotate the car. It just helps elevate the body for this task. If you have a cart that lifts the body higher than a long set of jack stands your ahead of many builders.
Some use a lift (supporting the body from the four center dolly locations) instead but many of us don't have access to that either for painting.
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Of course you can do it. Many have done it before. Just not as easy and for this task (where the floor needs to just sit as is usually does for the drips and epoxy top coat) a rotisserie isn't needed since you don't need to rotate the car. It just helps elevate the body for this task. If you have a cart that lifts the body higher than a long set of jack stands your ahead of many builders.
Some use a lift (supporting the body from the four center dolly locations) instead but many of us don't have access to that either for painting.
Thanks Jeff my car is currently on this cart. I was hoping that I could just apply the paint drips and not have to repay the bottom of the car, but not sure that that is an option. Unfortunately it appears I am doing some things out of sequence which is in turn causing the project to take longer and also causing some redo's!
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I have posted these before but bringing them up again may help someone. My car was a Metuchen build from MAR 66. These are pictures are as it left the factory. Notice the drips DO NOT only appear on the lowest valleys. Wet paint cannot run horizontally. Drips formed on the large flat areas too.
If you only create drips at the valleys of the formed ribs, it does not look "natural" at all. They were all over the belly.
Sort-of appropriate for this thread and probably appropriate to start another too are the three pictures runs, runs2, and runs3. This is the transition at the engine bay paint and transmission tunnel. These pictures show some data about how drips and pops may have developed on the belly. Clues to the drying methods are evident.
Keep in mind, this only applies to MY CAR. What I describe below may have been an "other than normal" thing that was done to my car because of some problem or skipped process or malfunctioning equipment. I lean more toward it being the NORMAL way things were done but Jeff and others have information that I don't have and they have much more knowledge than I do. What I do know with certainty is, the paint in these three pictures is original and factory applied. The black runs and sags are NOT caused during an after-production engine bay "freshen up."
I have discussed these pics with Jeff before and I think he disagrees with me, but I have years of experience in "root-cause" investigations in aerospace manufacturing, especially paint-related and I grew up in my Dad's body shop and am pretty good at paint analysis. I am absolutely certain that the red oxide and the black engine bay paint in these three pictures were the factory-applied coatings, in this transition area.
What makes me so certain is...the way wet black paint ran onto and INTO the red oxide paint. The only way this effect could have occurred is if the black was sprayed immediately after the red oxide. The thick coats of red oxide could NOT have formed a flash-coat-skin yet and the black mixed with the primer and the two wet coatings sagged in unison making streaks as they got more dry.
Another clue is indicated by the 90 degree change in direction of the runs. The long skinny runs are in an area where the red oxide is not nearly as thick of a buildup and has obviously formed a semi-dry skin. The skinny black runs are on that skin surface and gravity is in control. Then it appears the black runs encounter a strong enough forced-air stream that they sharply make a turn. This turn is not due to surface contour change because a "corner" that sharp does not coincide with the turn. A significant stream of drying blower air would have caused the direction change.
Maybe these pic's are a tiny piece of the puzzle. Who knows?
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Think the black and red primer sealer issues is likely a different subject than the focus of this thread (undercarriage drips) Just my opinion and also we need to reflect on the fact that Bryan's car is a 66 NJ car so we can't take its findings an apply them across the board. IF we have some more 66 NJ examples lets look at those and keep that focus in a new thread. Not certain that we did that when these were offered last time.
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As it pertains to drips (this thread) the forced air dry that changed the direction of the black paint runs give a
clue to how hard the blowers were blowing. That's all.