Media blast or dip?

[Cuda416]

In the next few months, I'm going to get started on my 70 Barracuda convertible project, at which time I'll start a thread. Up to now, I've done nothing to the car so to begin, I think I am going to need to strip it completely. Back in the day, media blasting with walnut was the thing, then it was soda blasting. There is also the option of dipping the car into something like evaporust which is non acidic.

First question is, whats the best option for something like that?

Second, what's the best way to treat the metal afterward? Seems like epoxy primer is the way to go but I keep reading you need prime the car within several days after. i won't be anywhere near ready to prime the car for paint in that short of a time. Clearly I'm missng something.

Any help is appreciated.


Thanks!

[JS29]

@Cuda416  You can do the body work over the epoxy primer. you want to prime it ASAP.     

[Cuda416]

Thanks, @JS29.

I know this is going to sound like I'm thick in the head, but one of the issues I've heard is once the EP cures, you can't prime over it without stripping it and doing the EP over again. Can you elaborate on the general process? The metal work doesn't scare me a bit. Steel is forgiving, paint is another story altogether.

[JS29]

I am an etch primer kind of bodyman, but they say you can wet sand PPG epoxy with a product called DX330.       It is like grease and wax remover and it prevents it from balling up and gumming up on the sandpaper. For some reason if you app lie surfacer primer over epoxy it dose not gun up when sanded. so if you do your filler work, wet sand the surrounding area, apply epoxy, then surface or high build primer you will be fine.   

[Cuda416]

Thanks again @JS29!

[Cuda Cody]

I prefer to media blast.  Dipping removes all the sealant between the panels that can not be put back in.  Plus all the anti rattle foam that keep things like the roof and hood from vibrating. 

[Rich G.]

Wiping it down with a good metal prep will by you some time . I've used PPG DP primer and never had any issues sanding it much later.

[JS29]

Wiping it down with a good metal prep will by you some time . I've used PPG DP primer and never had any issues sanding it much later.

I have not used epoxy primer in many a moon, Years ago i had the opportunity to attend the PPG paint school, that is were i learned about wet sanding using DX330. They were the ones that told of the gumming and balling up on the sandpaper. Has that changed, re-formulated? 

[anlauto]

I do a bit of both...media blast the entire shell, but chemically strip the body panels like doors and fenders. Always prime right away after stripping.

[torredcuda]

Wiping it down with a good metal prep will by you some time . I've used PPG DP primer and never had any issues sanding it much later.

I have not used epoxy primer in many a moon, Years ago i had the opportunity to attend the PPG paint school, that is were i learned about wet sanding using DX330. They were the ones that told of the gumming and balling up on the sandpaper. Has that changed, re-formulated?

Not sure how many years ago but DP went to lead free ( DPLF ), it has to be sanded if out of the time window (couple days I think?) so no problem there.

[torredcuda]

As to whether media or dip there are pros and cons to both, as Cody said dipping removes all the sealers and coatings and it`s pretty tough to put them all back and also leaves bare metal in side areas unless you could dip the whole body in primer - not sure if anyone can do that? Media blasting cleans all the exposed metal but doesn`t remove rust from those inside areas between panels or inside frame rails etc. I media blasted my Barracuda and do have some rust inside my rails but seeing how the car rarely sees rain, never salt and hardly ever gets washed  I doubt it will ever be a serious problem.

[Cuda416]

Thanks for all of the info. Not sure if this is the case, but the stuff I mentioned, Evaporust, only seems to attack corrosion and leaves existing pain intact. I've used it on small parts, stuff I could do in a bucket and I'm not sure if there are any companies using this stuff for cars, but I'd think it would be awesome.

So, question about media blasting etc. Since it cannot reach into all of the spots where liquids can, what do you do to deal with that? Are POR-15 and epoxy primers enough to prevent further corrosion?

[jimynick]

I think it kinda matters how much re-construction you're looking at. If, like many of us, you end up changing 1/4s and trunk/cabin floors, doors and fenders, then you're able to address each of them off the car and with usually good access. I had mine sand blasted- I know, I know - and they immediately epoxied the car. That epoxy stuck like snot to a blanket and did not ball up upon sanding. I've never been a big fan of dunking cars and Cody's warnings ring true to me. I'd blast the car and immediately get a coating of your choice on it and then you can take some time to proceed. If you're not able to epoxy everywhere, don't forget that rustproof systems like Krown work very well and that's what mine will get whenever I manage to final paint the damn thing. Have fun! 

[7E-Bodies]

I worked in auto body about 35 years ago. Obviously a lot has changed, especially chemically based.  I'm mid resto on a very valued product, I've found it helpful to print off the @Cuda Cody guide and follow it to the letter. https://www.e-bodies.org/how-to-paint-a-show-car-step-by-step-guide/
He explains well that you don't simply blast, then prime. A couple of extra steps, but man does it make a difference. I have it printed off and in a 3 ring binder right in my shop.