Boilerz25

I am looking to get my body shell, hood, doors and decklid blasted with walnut shells by a local shop but, they do not do paint work. So I am looking at shooting epoxy primer onto the entire body in and out to protect from corrosion myself. I am planning on then taking the car to a body shop to take over with the body work and paint. The question I have is how long will the epoxy primer be good for once it is applied? The reason I ask is I have yet to find the shop to do the paint work and would like to have the car ready. Since I am doing a frame-off, the rolling chassis will be fully assembled underneath the body at the point I shoot the primer. Also, should I spray a surfacer/primer such as Slick Sand on top of the Epoxy Primer base to further seal? I am a novice to this hence the questions.

Appreciate the feedback.

Sean

m371961

I am not an expert but epoxy primer if properly applied can be on for years if not exposed to sunlight. The shop that does the final paint however, may still want to strip it again. After all, they will be responsible for adhesion of the final job.

Boilerz25

I think it should be ok considering the body will be under a car cover and protected from moisture.

Thanks
Sean

jensenracing77

If you can keep it dry I would take it to the body guy with no primer on it. My body was blasted back in May and still not in primer. It was hauled from Indy to Brazil in an enclosed trailer and put into a dry body shop. Has no signs of surface rust yet. Should be in primer this week or next. My body guy wanted to do the major body work with it stripped. Let him prime it the way he wants.

69442C

Sean,
As others have mentioned, don't waste your time and money on priming the body as any quality shop will strip it off if they guarantee their work. So the money you spend on the primer will be a complete waste. If it were me, I would send them the body as it is when you remove it from the frame and let them take it from there. You may find a shop that can do their own media blasting so at least wait until you find a shop you plan to use so you can speak with them about how they want to deal with stripping the body and go from there. They may work something out where you get it blasted and immediately send it to them. But without having a clear plan on how the paint work will be done and by whom, I wouldn't do a thing until that plan is in place and in writing with someone.

NHolds

Just me, but I would apply epoxy immediately.

Boilerz25

The car will be protected from the elements after being blasted so I dont mind keeping it stripped until body shop takes over. I am however planning on at least priming and painting the firewall and underside so the body can go back on the frame permanently.

Thanks for the input.

Sean

oldstata

No expert here but on mine I stripped it did all body work and primed as I went. I agree a body shop would rather have it stripped with nothing on it and prime there selfs. How long do you plan to keep it before taking to a body shop ? Where will it be stored as bare metal rust supper easly any moister is bad. Watch how you cover it because it can hold moister in. I would acid etch then epoxy prime,that's what I did

Bernhard

As soon as the car is striped it should go into epoxy primer.
Rust never sleeps !!!!!!!

Take it to a shop for primer epoxy should be sprayed in a booth with safety gear.
Air has to be clean and dry.
The primer will be fine as long as it is not in the elements
The body shop will not have to strip the primer if it is a quality primer and applied.
correctly.
They should wipe down the primer with wax and grease remove and scuff before they start working on the body.

If using walnut the walnut shells have to have had the oil removed from the shells!!
Go to a shop that knows hot to strip sheet metal with out damage!
Walnut dose not remove rust!
Most good shops have a media that is specially designed for body panels,it is a mix off garnet abrasives that are very fine,some use glass bead!
They are very guarded with what they use if it is there own formula.
Plan this work for when the weather is good.

Look up best practices for bare metal I forgot the time line for striped metal before it goes into primer it is not days but Hours!
When the car is in the white before primer it must not be exposed to moisture!!
I think if you look up military spec you will find the rules for best practice.
Sorry it has been a long time since I have needed and followed the rules.

RonFX

Hey:
I am doing the same thing to my 66 Cutlass, a major body off restoration. I found an old school body guy who works w/ lead and is reasonable in pricing, I don't do a thing before I talk to Ed first. I was told who and where to take the body for media blasting, everything looks great when it gets back from the blaster. Ed told me to shop vac and blow out all the spots where the media could collect and wipe everything down w/ laquer thinner and a rag to remove any surface contaminants, I then spray everything down again w/ thinner from the spray gun and let it air dry before applying a 2 coats of Etch Primer to the bare metal, I apply a good heavy coat around the seams so it soaks in good in all the cracks and crevices. Make sure you use good name brand supplies as you go, no sense saving pennies on this level of restoration. Have fun, if it starts to get you down, walk away for awhile then come back. It only turns into a job if you let it, good luck!
Thanks Ron

Bernhard

Some good advice when it comes from the media blaster it should be free of media if they did it right but they sometime don't.
We were always told to use wax and grease remover before applying any primer/paint.
Prior to primer there are quite a few methods that I have seen done.
wax and grease followed by a metal etch wipe.
just wax and grease remover.
media blast straight into primer.
Non acid base metal prep and cleaner.


Some painters/shops liked to stay with in a line of products start to finish
because they were concerned with chemical reaction between brands.
Others used brand X wax and grease remover and metal prep.

Make sure that what ever you use that it is compatible with the next product that will be used.


Make sure air supply is free of oil and moister I have seen to many paint and body jobs ruined by contamination on the substrate.
Check the shop out to make sure they are clean ask what they do to prevent contamination.
I have seen paint work ruined by a bodyman over oiling his tools.

Napoleon Solo

Some good info laid out above. I own a media blasting company and we do auto restorations all of the time. Anyway, if you're interested in a blaster's point of view, typically I tell my customers to think of us second, although our work comes first. Tee up your body shop first, ask the questions, find out when they can take your car then schedule your media blasting for the day or two before.
Like Bernard said, walnut shell won't remove rust at all. It's great for stripping paint, primer, filler but not rust. All of our restos are a two stage process - first walnut on the sensitive sheetmetal bits (roof, hood, decklid, quarters, doors), then a processed 80+ mesh size garnet on everything else. Unless your blast shop buys walnut from farmer Bob, oil in the shells is virtually impossible. I get my walnut from California where it's kiln dried prior to packaging.
I don't know how rusty your car is but the places where it comes back quickest is where there is heavy pitting or severe rust. If there are areas like this it's likely your body man will want to cut them out anyway. I've personally stripped 'A' body frames where by the time I was done, the other end was already flash rusting and my shop is a very dry environment. On the flip side, I have some of my own parts I stripped 2 years ago, look like it was yesterday.
Be careful not to touch the stripped body without gloves. The oil on your skin will leave nice prints everywhere.
We have a 'sandblasting 101' page on our website for anyone interested in finding out more.

www.sureblast.ca

Solo out...

steverw

Im a believer in epoxy primer. PPG is probably the best but its expensive. Unless something has changed, they guarantee that it gives a 100% seal against moisture. They also say body fillers will adhere to it better than to bare metal, as in fillers like bondo, AllMetal, fiberglass, etc. No etching primer is needed if you use epoxy. PPG DP epoxy primers can be top coated up to a week after it is applied. If you wait longer it needs to be sanded like with 400 grit then reprimed. I have used it on numerous paint jobs and had great luck with it. There are cheaper epoxy primers but i have no experience with them. Usually PPG dealers also sell Shop Line paints, they have an epoxy primer, I suspect its probably a good primer but i never used it, however I have a gallon in my garage ill be priming my frame with when i get to that point. Epoxy can be top coated with any type of primer and paint. If i need a high build primer I do epoxy first, then use the high build, block it out then more epoxy to seal it then paint it. I have used bondo and fiberglass on epoxy and it worked great, as advertised.

oldstata

Primer does not seal from moister I used ppg primer and acid etch and in my window channel rust came threw I will up load pics tomorrow I had to clean it up granted my cover blew off and rain got to it

steverw

Did you use the PPG DP epoxy primer? My paint guy back home is the one who told me that PPG claimed it gave a 100% moisture barrier. However if the back side of anything cannot be accessed to de rust and prime I can see that rust could creep under the primed surfaces. Im no expert by any means, Im just repeating what the PPG dealer told me. Anyway I think its a great primer although very expensive now days as is most good quality automotive paint.

Bernhard

I have used PPG epoxy primer with good results,I don't know if it is the best.
I was also taught to apply plastic filler over it as well as plastic filler is like a sponge and can rust under the filler.
I always scuffed the area before I applied the plastic filler to the epoxy primed substrate.

Bernhard

Thanks for posting some very good info.

Do you know the military spec for handling striped metal
time striped to in primer and conditions that the metal has to be kept at when still bare.
I used to know this but it is lost like so many other things that i have learned.