Topic: Phosphating Hood Springs

[bullitt68]

I have now zinc phosphated 2 sets of hood hinges twice and both times I have had the same results. Not sure why, but rusty liquid keeps leaching out of the rivets even months later. I have tried boeshield and WD40 but for some reason I can't get the hinges to stop leaching. I have phosphated hundreds of parts and never has this problem before. FYI I am using Palmetto Hot Phosphating plating solution/process. Parts are bead blasted and and well cleaned before phosphating. I can't seem to get all of the water out of the rivets after the phosphating process. Any help or suggestions would be greatly appreciated. Not sure if stacking in evaporust will help or make it worse

[jwc66k]

Being that it's oil or grease, apply a solvent (kerosene, acetone, paint thinner, etc) with a spray bottle until there is no more crud coming out. Open and close the hinges several times. If you are not satisfied, try a five gallon bucket with solvent and soak the hinges. DO NOT USE GASOLINE. At one time, I had a five gallon bucket half full of well used Berryman's B12 carb cleaner that worked. And when you remove the hinges from the rinse water after phosphating, spray a lot of WD-40 in the pivot area - repeat.
Note: your hinges need to be a little darker.
Jim

[bullitt68]

Being that it's oil or grease, apply a solvent (kerosene, acetone, paint thinner, etc) with a spray bottle until there is no more crud coming out. Open and close the hinges several times. If you are not satisfied, try a five gallon bucket with solvent and soak the hinges. DO NOT USE GASOLINE. At one time, I had a five gallon bucket half full of well used Berryman's B12 carb cleaner that worked. And when you remove the hinges from the rinse water after phosphating, spray a lot of WD-40 in the pivot area - repeat.
Note: your hinges need to be a little darker.
Jim

Hi Jim FYI That is zinc phosphate. To go darker I would need to use manganese phosphate which would make the springs look almost black. So there is not really any adjustment. How do you suggest I make them a little darker

[lightwtjet]

I have done my hood springs/mechanism using Ospho.  You paint it on and wait 24 hours to dry. My springs are moderately dark afterwards. It is also an excellent rust preventing treatment. Ace has it $16 a quart.

[Bob Gaines]

Actually there is a way to adjust the shade.. By leaving the parts in the zinc bath longer well typically lightly darken . By limiting the time in the magnanese bath will typically result in a lighter shade. Of couse you need to play with a sample part that is prominently the same size and material to figure the right amount of exposure.

[bullitt68]

I have done my hood springs/mechanism using Ospho.  You paint it on and wait 24 hours to dry. My springs are moderately dark afterwards. It is also an excellent rust preventing treatment. Ace has it $16 a quart.

Thanks. I have that product as well and use if often, but I generally only use it on small parts and do bigger parts with the Palmetto method as it is faster and gives a very consistent finish and is generally easier to control the finish

[bullitt68]

Actually there is a way to adjust the shade.. By leaving the parts in the zinc bath longer well typically lightly darken . By limiting the time in the magnanese bath will typically result in a lighter shade. Of couse you need to play with a sample part that is prominently the same size and material to figure the right amount of exposure.

Thanks Bob. I can try a shorter boil time with Manganese, but the zinc will not get any darker as the hinges were left in the zinc solution for maximum darkening time. Normally I just submerge the part until the fizzing stops, which is generally a minute or so sending on the part/metallurgy and then remove and process

[Bob Gaines]

Thanks Bob. I can try a shorter boil time with Manganese, but the zinc will not get any darker as the hinges were left in the zinc solution for maximum darkening time. Normally I just submerge the part until the fizzing stops, which is generally a minute or so sending on the part/metallurgy and then remove and process

That is if you want them darker . From the picture the shade looked nominal to me.

[bullitt68]

That is if you want them darker . From the picture the shade looked nominal to me.

I have always used zinc on the hinges and manganese on the springs

[jwc66k]

Hi Jim FYI That is zinc phosphate. To go darker I would need to use manganese phosphate which would make the springs look almost black. So there is not really any adjustment. How do you suggest I make them a little darker

Did you read "Phosphating 101" in "Processes ..." section of this forum? I address shade by "adjusting" the initial acid percentage and total time in the hot 190F bath. I reread my write up. Is seems I been doing P & O for over 30 years now. I'm "tooting" my own horn.
Jim

[bullitt68]

Did you read "Phosphating 1101" in "Processes ..." section of this forum? I address shade by "adjusting" the initial acid percentage and total time in the hot 190F bath. I reread my write up. Is seems I been doing P & O for over 30 years now. I'm "tooting" my own horn.
Jim

No I have not read it, but I have been phosphating successfully for over 10 years now and I either use zinc or manganese, Whatever finish  the parts should be I just phosphate accordingly and take it out when it stops fizzing. I have never had a need to adjust, and have built concours cars with no issue. My theory is that the metallurgy and the phosphate will arrive at the right shade based on the process. I just want the part to be properly coated. So the question is should the hinges be zinc or manganese? I did the hood springs in manganese and of course they are much darker. But as a rule when the part is done when it has absorbed all the phosphate to the surface