I want to parkerize the support rods but the finishes in Steve's book says park./painted. Painting them black just doesn't feel right to me. I would like to hear from you officionatos. Black or Parkerize? What did you do?
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1930 to 1936 VL Front and Rear Support Rods
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Dear John, I'm also interested as it is rare to find unmolested bikes to check. Sometimes Harley parkerized, sometimes they painted or dipped over un-oiled pakerizing, and they may have done both during the 1930-36 period. I don't deduct judging points if the finish on the front and the rear footboard support rods is consistent.
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I painted mine with all the other black bits. Looks good to me, but then again, so would parkerizing. Like Steve says, as long as they're both the same...
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If you're going to paint parts and you haven't painted DIY parkerized parts . . . please, please note there is a massive difference between factory parkerization and what we can achieve at home.
The big difference is that the factory system was done under pressure and heat; it allowed a far more mild solution than what we use at home in almost every single manganese parkerizing kit. The parts also came out "dry" and very little if any flash rusting ever happened regardless of oiling of the parts.
Pretty much all home kits use a citric or phosphoric acid base to suspend the maganese and to key the part surface. Heat causes the surface reaction -- and the availability of carbon in the steel directly affects the final parkerization appearance. Hence, we have to more or less keep with non-chromoly steels (ie 1040 not 4140) and keep our temps at a relatively controlled 190-220 degrees for it all to work properly.
Where the problems start when you want to paint the part is in the "stopping" of the parkerization. When you pull a part out of the bath -- it will almost immediately get a surface rust on it when dry. This is partially due to the surface pores being way more open than you may think due to the heat - with both acid and metal bits exposed to oxygen. We tend to stop this reaction at home by immediately putting parts into a bucket or pail of oil.
If you're going to paint -- you need to be able to have a hot and a cold rinse to get all the crud out AND to close the pores before you let the part dry. Easiest way I know of is to plop parts into a boiling pail of clean, fresh water. If anything, you want to water to be slightly basic or ph neutral. But it must be clean water. Boil the parts for a few minutes and then transfer to a cold water bath. I have done it by running a garden hose into a bin and letting water overflow. After 20 minutes, parts are usually cool to their core. I then pull them out and dry. If I'm concerned about flash rust; I'll use acetone to wipe the part down (acetone can absorb up to 20% of its weight in water). That usually solves it by pulling all the water out of the surface.
When I've tried to paint over parkerized stuff without following these steps; I've had adhesion problems. 98% of those problems showed up as soon as primer hit the part. The other 2% showed up as "dust" rust under the primer that caused whole sections to lose adhesion overtime. Those were frustrating as they showed up 6 months or more after painting!
If I have made it through adhesion -- the second problem was crazing because I hadn't gotten all the acid off the part. Note, this later thing is a byproduct of the paints I use -- most urethanes and epoxy primers (DTM primers) hate any type of phosphoric or citric acid on a part. Conversely, most enamel or synthetic lacquer primers and paints can care less (hence why you can easily use "etching" primer with these paints but generally cannot with urethanes).
I'd be curious if others doing DIY parkerizing followed by DIY painting have run into similar challenges.
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