Zinc Plated Bolts Revisited

I started a thread months ago, about how to paint zinc plated bolts heads, to make sure the primmer would hold. I got lots of conflicting advice from both here and from other sources so I decided to experiment. I took three bolts and primed 1 with rattle can primer, 1 with commercial sandable automotive primer and one with PPG epoxy primer. Then, they were painted with Gillespie 24087. After a few weeks, I took an awl and tried to scratch them. The primer failed in all but the epoxy primed one. The primmer flaked off the other two but held on the epoxy. Just thought this may help others. I have now painted all my replacement bolts using epoxy primmer. Some nuts will need to be painted separately after installation. A picture of my bolt head paint board is below;

http://img225.imageshack.us/img225/3024/img0061rw7.jpg

Great info....THANKS for posting it!

Yes, Thanks for the info!

Good to know.....Now you gotta put all those bolts back in!

I hope the socket or wrench you'll be using won't harm the paint. I usually brush the bolt heads after assembly or assemble then paint. Thanks for the information, that's good to know.

Yea Randy, and thats not all of them. I've already replaced lots of non-painted ones!

Did you consider powder coating?

Zach

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Originally Posted by vacca rabite

Did you consider powder coating?

Zach

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The only problem we've had with powder coating fasteners has been that it changes the size of the fastener head once the powder is applied and baked.

Not sure if they make OD powder yet either.

I wondered about the OD of the nut issue. They have PC for jsut about every color under the sun these days. I'm sure the the army is coating some of thier stuff these days, but I can't say for sure one way or another. All the PC stuff that I have seen has held up way better then paint.

Zach

Did not consider power coating at all. And, last thing I need is more equipment!

I like powder coating in some applications but it is fickle. Here in the motorcycle world, some folks go nuts with it and it has to be done right.

For anything with threads, you cannot get it in the threads because you will then have to tap every hole afterward. Bolts just the same.

If you use it on any parts that have a close fit, like say a hole where a bushing resides, again you cannot allow the powdercoat to get in there because it changes the diameter of the hole.

If the powdercoater isn't attentive and misses a spot, you can't go back and touch it up. You have to redo it totally. Not fun.

Which leads to the next issue. If you have to remove powdercoating, there is almost nothing that will take it off easily. Aerosol gasket stripper or aircraft stripper will soften it, but still it requires lots of work to get it off before you can then sandblast. Sandblasting alone barely scratches the stuff.

If you chip powdercoating, as above you can't touch it up. It has to be redone. You can touch up with matching color paint, but you negate the purpose of powdercoating in the first place which is a seamless membrane against the elements.Also notice a snow plow or winch mount after a few years in service. They are generally powdercoated, and one the surface is broken and moisture gets beneath the surface, the rust will spread much further and not show up until it lfts and bubbles the powdercoat.

In restoration circles we hate it because it takes alot of the detail away from parts as well. Particularly with cast parts, stamped numbers, and the like. This is only an issue in correctness of a restorationa dn may not apply in everyday use.

Aall that said it does have its place for bracketry, undercar parts, and things that see severe duty because powdercoating is more resistant to scratching and chipping than paint.

Great info. This is why it literally pays to be part of fourms like these. Getting the ability to pick the brains of pros really helps from trying to reinvent the wheel at times.

Zach