Best way to remove frame epoxy

[Nick774]

So Ive been sandblasting what I can on the frame to remove the loose epoxy chips and rust. However the majority of the frames epoxy is still well bonded on. The plan thus far is sandblasting to reveal every rusted area, cut, and weld in new sections. Two good layers of POR 15 and then prep to be reassembled. What is the best product or technique to remove the epoxy?12871 this is an old pic, the frame is complelty stripped right now.

[WelmoedJ]

So Ive been sandblasting what I can on the frame to remove the loose epoxy chips and rust. However the majority of the frames epoxy is still well bonded on. The plan thus far is sandblasting to reveal every rusted area, cut, and weld in new sections. Two good layers of POR 15 and then prep to be reassembled. What is the best product or technique to remove the epoxy?12871 this is an old pic, the frame is complelty stripped right now.

I'm not saying you shouln't use sandblasting.
However, this way you will have a lot of work and little result.
Sandblasting if all epoxy has been removed, will be better and take less time.
This sandblasting will not be needed if you follow the below described process.

Over here (Europe, Netherlands) I have experienced that using heat (special ovens) removes all of the epoxy.
Make sure to clean out the inside of the frame as there will be a lot of remains in there.
It may take more time and effort:
- Transport to and from the facility that does the coating removal.
- Cost of having it done.

Most of the frames need repairs after coating removal, so this is the moment for judging the condition of the fram.
After frame repairs we have the frame treated with zinc (galvanisation).
When that's done, it gets a powder coat.

Hope this helps you decide how to proceed.

[Bitsyncmaster]

You can probably get most of with a torch and scraper. Would be faster than sand blasting. The clean up with sand balsting.

[WelmoedJ]

You can probably get most of with a torch and scraper. Would be faster than sand blasting. The clean up with sand balsting.

Using a blow torch will only help to remove the epoxy on the outside of the frame.
The high temperature probably will also burn part of the epoxy on the inside, but will never get it off as good as an oven does.
A partially removed coating on the inside will never ensure a good surface for a new protective coating.

It will cost (often much more than) a bit but it will ensure a totally clean surface, outside AND inside.

[Spittybug]

Short of a torch, perhaps just a high heat electric heat gun? I would guess that it would start to bubble up and then you could give it a quick scrape with a putty knife. That might work and give you less chance of burning it and the mess that could cause. I'd be interested to hear if that works.

[Chris 16409]

Just douse the frame in Brake Fluid and wait a week. The epoxy will just melt off! :tongue:

[DMC3165]

I think the torch and scraper method would work best Nick. If it was me I'd sandblast it after you've got it down to bare metal. In the past I've done work like this on class 8 truck chassis and have found rotten metal far beyond what was visible to the naked eye. A few good raps with a welding hammer will reveal alot of fatigued metal as well.

I hope the frame is salvageable. I still think you might be better off with a replacement if you can find one at a reasonable price. Good luck!

[DeloreanResto]

It has to be Acid dipped to weaken the epoxy.. then you finish with Sandblast.... It is possible to remove with a Sandblaster but you have to use a different more expensive sand...

[Nick774]

Hello again guys! So as far as the frame goes I've used the torch and scraper method and cleaned up a decent portion from the rear engine bay tail bar up to the mid section in front of the trans. This is however a lot of time and gas so i would prefer to have it baked. I've taken it up to a place called Quick Strip in Carteret NJ, but they were unable to blast it. We tried numerous media on it but no luck. We even tried some heavy duty stripping agent but nada. He then tipped me off to another shop that does automotive baking but they said they don't have a big enough oven? Ive been scowering the internet tryng to find a shop but nothing. So now Im back to square one and Im really trying to have the frame welded and POR15 by the end of December. Does anybody body In or near New Jersey Know of where I can bake my damn frame :dunno:

[David T]

Maybe a BIG bonfire! What you need is a torch like the roofers use to put down roof coatings. And an ice chopper. You don't have to get it perfect, you can finish small spots with sandblasting. Most shops with ovens will only go up to around 450, not enough. It will soften the epoxy but as soon as it cools it will get hard again.
David Teitelbaum

[Nick774]

I agree completely and wish I had a giant oven! I'm also concerned about warping the steel. When I was using my small hand torch I noticed the surface would buckle somewhat.

[DMCMW Dave]

There are only really two ways to get a frame completely stripped - I've done both:
Chemical (Redi-Strip is the only one that works)
Burn-off Oven (Finding one large enough for the frame is dfficult to impossible, we got lucky on this one)

I prefer chemical although it is easily 2x the price of burning it. It looks much nicer when it comes back.

You can't sandblast it off, and the heat -n-scrape-by-hand method completely ignores all the boxed in sections. As you are finding it takes an insane amount of work. And there is nothing quite like the smell (and probably bad chemicals) of burning frame epoxy.

[Delorean Industries]

Realistically for the finish to last you need to do both. We burn off in Sandusky, bring the frame back and perform any required repairs, chemically strip to remove any impurities followed by acid dip, coating with paint ready gavanizing (there is a difference) and powder coat for appearances only.

Powder coat only is not a solution as bonding a pliable layer of powder into all areas is impossible no matter how good the application is.

[DMC3165]

Nick, i'm curious what the frame looks like now that you have everything removed. Could you post a few pics of what it looks like? I'm curious how extensive the damage is and what Josh and David's opinions are on its overall condition. I remember what I saw last but I never had the chance to see what your looking at now. Some of the vendors or guys like David T may be able to help guide your repair without stripping the entire frame and making only the nesassary repairs as needed to get it road worthy again

[Nick774]

Here it is guys Vin 774s unforntunate frame, sorry it too so long.
On the back end surrounding the engine bay is where I had been baking the epoxy off and since then has grown some light surface rust from the elements but not as bad as it looks in the photos. In fact the entire frame despite its faults is more appealing in person...anyways

15107151081510915110151111511215113151141511515116 151171511815119

I will be able to weld all areas in need, verdict?

[David T]

The frame does have a lot of "issues". If you have to send it out for repairs it would probably be cheaper to find another frame. The "good news" is that if you are handy with a grinder and a welder you can do it yourself. The frame is made up of 16 GA mild sheet metal. You can cut out the rot and fab up small patches and fix each area. Materiel costs will be very low, it is all about the labor. Even the tools required are not expensive except for a welder. If you have to you can even gas weld it with an acetylene torch but that takes a little more skill and practice. The last section of the Workshop Manual has a layout of the frame with all of the critical dimensions. Even if you were to get another frame it may also require at least some repair. At least this one looks straight! If you are timid about welding inquire at the local Technical school, many offer classes in welding. It is a lot like sewing, it takes some skill but a LOT of patience.
David Teitelbaum

[Nicholas R]

Someone once told me "if you can ice a cake, you can weld." I'm not really sure what made that person an authority on either though. Plus in my case, I'm a halfway decent welder but I cant ice a cake for crap. Welding isn't too tough, just takes a steady hand and practice. You can read all about it but really the only way to learn is to do it and learn what does and doesn't work. The nice thing with welding is that, in most cases, if you mess up, you can just grind it out and redo it. (unless you burn holes in your workpiece). Always better to start with lower heat and work your way up to be safe.

[Nick774]

I happen to be quite crafty with welding actually! I am the mechanic for Iplay America here in Freehold and I have a Miller matic in the shop. Last spring Meghan surprised me with a brand new Lincoln 225 stick welder. I have been experimenting and practicing with 16g steel already and my seven years as an arts major makes this like a second nature. I really enjoy the craft and have been tack welding a ball bearing roller coaster I have designed just for kicks on the side :) I will be doing all the welding myself and while teaching Meghan how to weld too. Shes as crazy about this car as me and she has been a real rough neck in tear down process. Just the two of us raised the body with ease! Anyways not to wander off topic, I will be patient and precise with my work to this frame and I have the POR15 Grey ready to go. This is the key stone of the restoration for me and It needs to be solid.

As you can see I had some trouble removing the trailing arms as the brakes cables are rusted in tight. And Nick I was curious where you found the stainless braided fuel line kit for your car? I do not wish to use the hard lines as they are heavily corroded. I plan to fabricate entirely new crumple tubes as the whole front section is probably not the best anymore. This car sat for nearly twelve years on grass under a tarp in Queens. Im still having trouble finding a place to strip it as well, i found a place called Redi strip and Kwik Strip but both are now closed. I know I can just work around and leave the better areas but I would most definitely prefer to have it stripped.


-Nick

[WelmoedJ]

From your description I presume you will reach an almost perfect frame, once done.
Though there's a lot to work on, this frame is not as bad as the one that survived Katrina.
I've seen that frame at DMC EU shortly after it fell from underneath the body.

Yes, it fell front and rear part separately to the garage floor.
Turned out the middle section was totally rotted away.
The bolts in the body held the front and rear to the body.
Of course this car had a perfect and sweet dampening of road unevenesses :hysterical:

[Malevy]

Not the worst I have seen, but many frames have been replaced over the years that don't look that bad.

The last 2 photos are of the engine? Looks like you have some block rot there.

Most people would have parted this car out.. Glad you are taking the restoration path to save it.

[Nick774]

That is exactly what that is, Block Rot. Is this the end for this engine? I would assume so unless some believe it is salvageable, I would prefer to keep the block if I can.

[Malevy]

It may be (can't tell from the photos for sure), but why risk it? It would stink to dump money in to rebuilding this block, only to have problems down the road.

[David T]

If you are that familiar with welding, then fixing up the frame is going to be simple for you. All you need are a few sheets of 16 GA sheetmetal (and a lot of time!). There is no reason to obsess over the block. The motors are not numbered to the car so it is not necessary to try to save an unsaveable block. You are correct in that the frame is the foundation of the whole car and you do need to start with a good, solid, straight frame. You can either cover it with POR-15 or find a shop that will hot-dip it in zinc. The zinc will add a few pounds, the paint will not. The zinc will last longer but if you keep the car inside and not parked on dirt it will last a LONG time even if you only paint it. I would not recommend stick welding it, too easy to burn through. It is a lot easier to control and weld thin materiel with a MIG welder. For the utmost in control I find gas welding is the best method but it takes a lot of practice and is a slower method than MIG.
David Teitelbaum

[DMC81]

There are only really two ways to get a frame completely stripped - I've done both:
Chemical (Redi-Strip is the only one that works)
Burn-off Oven (Finding one large enough for the frame is dfficult to impossible, we got lucky on this one)

I prefer chemical although it is easily 2x the price of burning it. It looks much nicer when it comes back.

You can't sandblast it off, and the heat -n-scrape-by-hand method completely ignores all the boxed in sections. As you are finding it takes an insane amount of work. And there is nothing quite like the smell (and probably bad chemicals) of burning frame epoxy.



Does anyone know what temperature the frames are baked at and for how long, going with this method?

[Delorean Industries]

When we still refurbished mild steel chassis (during the dark ages) this was performed as a multi staged process. The part must be brought up and down from temperature as not to warp and distort. We also had a fixture for holding in the oven as it would want to twist if just left sitting on a cart. We were acustom to 14 hour sessions ramping up to 850+ with a bath between to wash out ash once cooled and pickling at the end. A heck of a lot of work for a piece that will never be properly coated. I was never comfortable with the final product and gavl finishes are horrible. Best solution we found was e coating. Still not a great solution as dipping is the only way to properly do this component. To my knowledge no one offers this for such a large object. (as of 2014)

[David T]

Finding an oven large enough and hot enough is not easy. One way to remove the epoxy is with a plumber's torch working on a spot at a time with a scraper. It will be a long, tedious, messy, and smelly job but it could be done that way. If the epoxy is in good shape you may only have to deal with certain bad areas, not the whole frame. Just remove the epoxy from where it is loose and spray paint those spots. As mentioned in the previous post, if you bake the frame you must take precautions to prevent distortion. The way to go would be to find a Redi-Strip or similar place that can strip the epoxy for you. Probably easier to find than an oven. As soon as the frame is stripped you must get something on it right away before the steel has any chance to rust. At least a primer or a Chromate dip. Zinc coating is expensive and will add weight besides messing with all of the holes. They will all have to be drilled and tapped to remove the zinc so you can assemble the car back together.

[Josh]

Does anyone know what temperature the frames are baked at and for how long, going with this method?

700F for 4 hours in a burnoff oven.
Chemical dip is better, but not available to me

http://dmctalk.org/showthread.php?6959-VIN-11408-getting-it-back-on-the-road!&p=111948&viewfull=1#post111948