Cure for flaking powder coat

[cabrioman]

Talking chassis coatings with Mike, he thought some people may be interested to see how I resolved my flaking powder coat problem, which quite a few of us have had issues with.

My Hunter rebuild started out with the intention of a quick clean up but the more I pulled off it the more powder coat disasters I found. A brief foray into Hydrate80 and POR15 paint treatment proved frustrating as the finish wasn’t what I wanted and it reacted or didn’t stick well to the powder coat.

The answer was drastic action, getting the chassis properly prepped and recoated.

The pictures below show the chassis in the blasting plant prior to recoating. I went to have a look at it at that stage and found where it had been blasted, the metal surface was textured like it had been etched, it certainly wasn’t like that where the original powder coat flaked off, so I can only assume the chassis were not blasted in that way when first coated.

The powder coating company applied a zinc powder primer coat before coating with black top coat as per the original finish.

Was it worth it? Well for me it was, I had to paint it anyway as I had cut the bulkhead to accommodate the BMW M20 engine and welded new repair sections in the transmission tunnel where it had been modified by Marlin to take an auto box conversion. And having it blasted sorted out the corrosion that had occurred with the original powder coat, something I could never have got as good by elbow grease, wire brush and sandpaper.

A tin of POR15 is £45, Hydrate 80 is £20, my solution was less than £350, more expensive for sure but I think worth every penny.

So just got to put it back together now, but at least all the holes are drilled!

[jeremy]

That is a superb job, and the proper way to start a rebuild...when you consider the hours of prep to do it yourself, I think 350 is well worth the final result..will last for years.

[Patrick]

Very nice, this is how they should have all been done out the factory! I'd like to do this with Sportster chassis some day, in addition to getting rid of bubbling powder coat I want to clean up all the welds too.

[denniswpearce]

A beautiful job on the chassis.

I have looked at my chassis all round and under but it all seems to be ok, no flaking or rust, so am I lucky or is the powder coating from Marlin that bad as most of you have issues with it.

[peterux]

Yes, indeed, John's chassis now looks as good as new!

Although I have to say that I've not had any issues with my Marlin supplied powder coated chassis. I've not spotted any rusting, flaking or bubbling.
It's now in a nice dry garage but it spent the first 4 years in an unheated lock-up and we've been in out in the rain many times over the last 4 years it's been on the road.
...peter

[Patrick]

I've been putting mine up on the ramps once or twice a year patching stuff and I avoid driving in the rain and keep it in an insulated garage.

[peterux]

Originally Posted by Patrick

I've been putting mine up on the ramps once or twice a year patching stuff and I avoid driving in the rain and keep it in an insulated garage.

Oh dear, that is bad news...

[Patrick]

it tends to be around the rear where the suspension attaches and directly under the rear passenger area - its been fine up the middle and around the front. You get these little trails under the powder coat when removed show small amounts of surface rust. The roll bar / chassis paint I use matches the powder coat really well and seem to fix the effected areas long term.

[Chris Cussen]

Mine was flaking on the sills and along the rear floor plan.

[denniswpearce]

Originally Posted by Patrick

it tends to be around the rear where the suspension attaches and directly under the rear passenger area - its been fine up the middle and around the front. You get these little trails under the powder coat when removed show small amounts of surface rust. The roll bar / chassis paint I use matches the powder coat really well and seem to fix the effected areas long term.

Presumably then to rectify an infected area, if it happens to mine, is to remove all powder coating and rust and then prime and paint with a matching coating ?

[Patrick]

Pretty much this spray paint is one I've used in the past: http://www.cbsonline.co.uk/mobile/pr..._Aerosol_PNCHA

My currently can is different, I need to check where I got it.

[GreatOldOne]

I've been using this from frosts:

http://www.frost.co.uk/eastwood-extr...atin-397g.html

Expensive, but it covers well, and so far is more than up to the job. Good match to the original powdercoat as well.