POR15 Topcoat

[ChrisH]

Been lurking for a long time and finally decided it was time to try to contribute and I need some advice.

I have an '83 chassis that got 2 coats of POR15 and 2 coats of POR15 topcoat. The topcoat can easily be scratched off exposing the base POR15 underneath.

My prep:
Sandblast
POR15 Metal Prep per the directions
2 Coats of POR15 per directions
Let it sit for a few days
Scuff w/320 grit sandpaper
2 Coats of POR15 topcoat per the directions
Topcoat did not stick......

My question now is what should I do to take the topcoat off without hopefully damaging the good base underneath? I have contacted POR15 for advice and get mixed info all of which sounds suspect.

I would like to get the topcoat off and hit the base with an etch primer and decent epoxy spray bomb if possible.

In hindsight I should have just ponied up the cash for powder coat or have someone spray it with epoxy paint. I have more money in materials and time than I thought I would ever have and just need to cut my loss, get it in decent shape, and move on.

Any advice would be appreciated.

 

[chengny]

If the bond between the base (POR-15) and the top coat is failing, the way I see it, you have 2 options:

1. Handtool/sandblast the top coat until it is completely gone. If the regular POR-15 was properly applied, it will remain bonded to the substrate. Leave it like that or try another top-coat application.

2. Do nothing. Just let the top coat flake off naturally. Leave it that way. It may not look as pretty - but afterall, it is a truck frame. The base coat POR-15 will remain in place and provide protection for years to come.

 

[ChrisH]

Thanks Chengny. I'm thinking I'm going to hit it with some medium grit sandpaper and see how it goes.

I thought about just leaving it and letting it flake but I did a gray base coat with black topcoat and i would hate to see that. I thought it would be smart that I could see what I was coating instead of all black. Now I wish I had done all black.

 

[chengny]

When top coating, the color of the top coat should always (or whenever possible), match the base coat.

I think they must cover that subject in "Auto Body 101". Whenever I go to have a vehicle repainted, getting the body guys to change color is like pulling teeth.

It's a good rule of thumb.

 

[ChrisH]

I learned my lesson on this one. Hopefully I will get a chance to work on this in the next couple of days between some other projects.