Opinions on acid/chemical dip for panels, and alternatives

[ck80]

[Edit/disclaimer - looking at rust removal, not encapsulation]

So, pre-covid there were nos fenders and the like all over. Since, haven't seen anything worthwhile for sale, just the same POS/overpriced eBay crap that's been listed and relisted with no bites for 3 or 4 years straight.

No interest in repop trash and decent 50 year old parts are harder to find since they stopped making real trucks, everyone wants the old stuff now.

So, I had the chance to get some original gm tooled used pieces that are nice, but, have an issue. There's light surface rust in the seams where the layers of the fender crimp together. I bought them anyways because something is better than nothing, and I can always use them elsewhere or in the future (if not just resell them.)

So, while media blasting will take off the 2 layers of paint and such, it is NOT going to get everything out from between the layers.

However, back in the day I know rat rod guys used to acid dip stuff to actually lighten parts by eating away some metal thickness... and that is a side effect I DONT want.

Another complication is I hear it can be hard to get all of the acid residue out from between the same layers I want the rust eradicated in. So, I'm guessing maybe there is some type of neutralization bath out there that helps with that?

And post steip, dip, or whatever else, is it worth having some type of coating applied, and if so, which would be best as to not interfere with paint adhesion?

The panel is remarkably straight overall, it's just an outdoor vehicle of that age had the rust start, and, going through the effort to replace and do paint work, I'm not doing wait with an eye of having rust creep back out 8 or 10 years from now due to the foothold it has.

So, thought/opinions? Best world I find some nos pieces reasonably priced, but in the meantime I plan to recondition these to the best they can be.

Bad picture, but you can at least see some orange/tan between the layers.

 

[pagrunt]

What about Eastwood's rust encapsulator (https://www.eastwood.com/search/?q=encapsulator) or heavy duty anti rust (https://www.eastwood.com/eastwood-heavy-duty-anti-rust-in-black.html).

 

[superbon54]

The modern professional acid/chemical removal outfits can do it in a way that does not eat away at the steel. I’ve had my body tub, hood and door inners all dipped. I had the tube e-coated immediately after and it was fine. There is a neutralizer applied after but I did have wait a bit after to paint the other bits because any acid left that leeches out will ruin it.

If you go forward with it, be prepared for everything to look way worse coming out than when it went in. There is a lot that hides below the surface.

 

[565bbchevy]

I would say have the panel so the gap is vertical an pour a little POR 15 in there a few times letting it cure

 

[Wraith]

I'm a DIY chemist, deal in car wash chemicals for my real job.

If they were mine I'd mix up a concoction of wheel acid and spray them down watching the change on them. Then I'd mix up another alkaline mix to neutralize it all, blow drying it with air and heat gun in nooks-and-crannies to prevent as much flash rust as possible. Before primer I used Sherwin Williams W4K288 Metal Etch or a similar product. I had to do this with one fender as I wanted to use GM not repop fenders. Since my car was stripped and bare metal I used the Metal Etch on the entire car before primer.

 

[ck80]

What about Eastwood's rust encapsulator (https://www.eastwood.com/search/?q=encapsulator) or heavy duty anti rust (https://www.eastwood.com/eastwood-heavy-duty-anti-rust-in-black.html).

I would say have the panel so the gap is vertical an pour a little POR 15 in there a few times letting it cure

Thanks for the feedback so far, but.... Well, I'm not interested in any type of "encapsulator" or "neutralizer" coatings. There are so many seams at so many angles, it's not going to seal it all, it just won't.

Here's some pics of the volume of seams. Basically the whole perimeter is involved.

The amount of flipping, twisting, contortions, and then having exposed surfaces where the stuff is glopy drippy, running, what have you.... not for me. Plus, that's just a cosmetic bandaid... even if it did fully penetrate (which I doubt) it's not removing the rust which is what I'm after. Still, for a broken truck repainted blue once they're pretty decent compared to Chinese.

The modern professional acid/chemical removal outfits can do it in a way that does not eat away at the steel. I’ve had my body tub, hood and door inners all dipped. I had the tube e-coated immediately after and it was fine. There is a neutralizer applied after but I did have wait a bit after to paint the other bits because any acid left that leeches out will ruin it.

Any recollection on how long they recommended you wait, and, did that apply to everything or just the parts that weren't e-coated?

If you go forward with it, be prepared for everything to look way worse coming out than when it went in. There is a lot that hides below the surface.

If there was a set/pair of nos ones within driving distance and not owned by a crackhead asking over $1000 I'd gladly go that route and save time/effort. But if I can put less than $400 each into getting what I have rust eradicated and straight I'd probably be willing.

I've got a used but straight and unpitted OEM core support and brackets setup, plus wheelwells, I plan to have dipped and powdercoated once I find a place for it. My hope is someone will be able to handle the fenders too, but, I need to know what to really look and ask for. Never went down this road before.

 

[ck80]

I'm a DIY chemist, deal in car wash chemicals for my real job.

If they were mine I'd mix up a concoction of wheel acid and spray them down watching the change on them. Then I'd mix up another alkaline mix to neutralize it all, blow drying it with air and heat gun in nooks-and-crannies to prevent as much flash rust as possible. Before primer I used Sherwin Williams W4K288 Metal Etch or a similar product. I had to do this with one fender as I wanted to use GM not repop fenders. Since my car was stripped and bare metal I used the Metal Etch on the entire car before primer.

Except for the drying part of the equation, I wonder about getting a pair of large kiddie pools on seasonal clearance, then fill them up, submerge the panels, then move then to the alkaline dip? Does leave the possibility of fresh rust reforming in the same darn seams though since no primer could oenetrate inside properly.

Don't want to be one of those guys with $20k in a truck he just finished and have paint (and thus rust) already bubbling back up from crevices and trim.

 

[Wraith]

Except for the drying part of the equation, I wonder about getting a pair of large kiddie pools on seasonal clearance, then fill them up, submerge the panels, then move then to the alkaline dip? Does leave the possibility of fresh rust reforming in the same darn seams though since no primer could oenetrate inside properly.

Don't want to be one of those guys with $20k in a truck he just finished and have paint (and thus rust) already bubbling back up from crevices and trim.

I would say that would work, flowing something between the panels would be the best to help prevent future corrosion but I don't believe you will ever get to every spot inside with nearly anything that could prevent all future problems, tens of years down the road. Unless there is someway to flow either an epoxy primer or DTM primer and let it float through, it will come back albeit slower than before. If you've ever seen people that don't paint over the aftermarket metal and leave in the black it ends up rusting too, the same will happen in the same nooks and crannies. It's all a compromise at this point.

 

[ELCAM]

Research Rust Removal using Electrolysis and zinc plating at home.

 

[69hurstolds]

Am I seeing things or do I spy a stamping that says your fender in the last picture was made in Taiwan??? I don't even know what year you're discussing, but I'm guessing the OEM didn't have it made in Taiwan. Or am I missing something?

Edit: Oh, I see that the shape appears to be the 73-80 GM truck fenders.