Paint Removal

[Chuck51631]

Does anyone know the best way to strip a car down to bare metal?

Money is limited so I am thinking of this as a do it yourself project before sending it to the shop for painting.

I have been told that sanding is the best method.

I have been told sand blasting warps metal.

I have been told chemical strippers damages rubber and plastic parts.

Any advice is welcome.

Thank You for taking the time to respond.

Chuck

[Dave72dt]

Each has advantages and each has disadvantages.  Sanding is easy on the metal but very time consuming and tough to get into tight places.  Doing it yourself, not a big deal.  Sand blasting done wrong is a big problem, done correctly, not  Media other than sand can be used,  These also have pluses and minuses.  Chem strip is very effective, get's in everywhere, can be hard to get out of everywhere and haunt a paint job later.  You'll want the plastic and rubber pieces off the car regardless of the type of stripping you do.

[Young Ed]

Dave what are your thoughts on the 3m rubber things you put in an angle grinder?

http://www.amazon.com/3M-SandBlaster-9681-2-Inch-Clean-N-Strip/dp/B000BQURDI/ref=sr_1_1?ie=UTF8&qid=1361384449&sr=8-1&keywords=3m+stripper+disk

[Joe Flanagan]

Get a 9-inch Makita angle grinder and hit it with 90 grit sandpaper. That should get everything but the crevices. The places you can't get with the grinder, hit with a Speed Blaster.

[Uncle-Pekka]

My question is "why do you want to strip it to bare metal all over?"

 

The way I did it: 

- removed fenders and took them to media blast

- removed doors and soaked the bottoms in citron acid in my own garage in simple do-it-yourself pools. After wash and baking a coat of epoxy.

- removed paint from suspicious looking areas by nitromors type of paint remover chemical

- healthy areas, such as the roof and the hood, I just sealed by epoxy 2 component paint

 

I disagree the opinion, that sanding by angle grinder would be easy on the metal. No way. It produces similar highly reactive surface (corrosion prone)  as sand blasting.

The environment must be 100% dry from atmospheric moisture if you think you will be able to lay a sealing paint coat before micro-corrosion will hit the surface.

Thus I cannot understand what good it will ever do to sand the entire body to metal...

 

Corroded areas need to be stripped, rust removed and area sealed. It does no good to strip paint away from healthy areas wahen you have inexpensive paints that will seal old coats forever. 

[Dave72dt]

Dave what are your thoughts on the 3m rubber things you put in an angle grinder?

http://www.amazon.com/3M-SandBlaster-9681-2-Inch-Clean-N-Strip/dp/B000BQURDI/ref=sr_1_1?ie=UTF8&qid=1361384449&sr=8-1&keywords=3m+stripper+disk

I have discs of that material setup as a roloc and used a bunch on Mark's truck.  4 1/2 ' grinder would work better to save on the air compressor although they don't last that long.   You can get them in a bigger size to fit a 7-9" grinder which I would prefer for the time savings.  These things also create heat which can warp a panel as easily as sand blasting can do.  Purple ones last longer than the black ones.  I find sanding discs loose their cutting ability quickly when they hit rust and bare steel but they will remove some rust the abrasive wheel can't get to.  Usually use a combination of methods to get as much rust as I can.  I've found really thin metal under what looks to be solid paint so i take it all off these older vehicles.

[james curl]

I have used a 6" Porter Cable oscillating orbital sander to strip my 55 Chev pick up and a friends 51 business coupe to bare metal.  I used #60 grit hook and loop sanding pads which I buy from a commercial supplier on the Internet.  I also used the same sander and a mate that I purchased at Lowes to strip my 1921 built house to bare wood, the house is 40' X 50' with a wrap around front porch and four gable ends.  They now hang from the peg board in the garage ready for any thing that I can throw at them.  They resemble a right angle grinder or the polisher from Garotes garage or Mothers wax.  They are variable speed sanders and I have always used them on the high setting.  They come with a peal and stick pad which is useless as the adhesive lets loose when the paper gets hot.

[Plymouthy Adams]

blasting done right is not a problem..... painted surface is not part of the steel making process so somewhere in its life it has started out as bare metal..old paint under new is something I have no desire for..you will have to use a midcoat sealer to do that job right...added step added cost.....but if you do not wish to go to bare metal I will not condemn your actions, your car your call....a DA will take the surface paint off and get you to the primers beneath and this I do recommend...and metal is not sacraficed... I just blasted the fenders on the coupe this past weekend..they looked so-so  to begin with but like a leper with rust splotches beneath the original primer...by pure experience this I knew I would see..though color is still on the panel it is so thin with age over time that the ability to hold out moisture is for naught...primer is porus..thus the eventual sploty rust on surface is not only expected, but a guarantee...now of course this rust was not the case when primed...and if you think so..then 67 years laying dormant beneath the paint from the factory speaks well for metal that was bare fromt he get-go...further you can do all you wish and if it is the case of staying in primer and exposing primers to the elements prior to a top coat...by not being fluid in the repair and keeping the process flowing smoothly and timely between steps without subjecting primer to the elements (epoxy is exept from my scenario)...you are sbujecting the substrate to moisture and oxygen..the two titems when combined is the motral enemy of bare metal.

[Daliant.]

Dave what are your thoughts on the 3m rubber things you put in an angle grinder?

http://www.amazon.com/3M-SandBlaster-9681-2-Inch-Clean-N-Strip/dp/B000BQURDI/ref=sr_1_1?ie=UTF8&qid=1361384449&sr=8-1&keywords=3m+stripper+disk

Those disks are awesome, they even eat rust out of pitted metal. I like to use a combination of clean n strip disks and chemical paint stripper whenever I take something down to bare metal.

[Joe Flanagan]

I disagree the opinion, that sanding by angle grinder would be easy on the metal. No way. 

 

 

Stripping cars with sandpaper on an angle grinder is done all the time. I know of a shop in New Jersey that uses the 9-inch Makita grinder and 90 grit sandpaper routinely. It will produce enough heat to warp the metal but only if you really overdo it in one spot. 

Edited February 21, 2013 by Joe Flanagan

[Robert Horne]

I use my Asian stripper (Kawasaki) when removing paint or rust.

The twisted wire brush last alot longer than non twisted wire..

Later use the DA sander...

[55 Fargo]

My question is "why do you want to strip it to bare metal all over?"

 

The way I did it: 

- removed fenders and took them to media blast

- removed doors and soaked the bottoms in citron acid in my own garage in simple do-it-yourself pools. After wash and baking a coat of epoxy.

- removed paint from suspicious looking areas by nitromors type of paint remover chemical

- healthy areas, such as the roof and the hood, I just sealed by epoxy 2 component paint

 

I disagree the opinion, that sanding by angle grinder would be easy on the metal. No way. It produces similar highly reactive surface (corrosion prone)  as sand blasting.

The environment must be 100% dry from atmospheric moisture if you think you will be able to lay a sealing paint coat before micro-corrosion will hit the surface.

Thus I cannot understand what good it will ever do to sand the entire body to metal...

 

Corroded areas need to be stripped, rust removed and area sealed. It does no good to strip paint away from healthy areas wahen you have inexpensive paints that will seal old coats forever. 

I agree Pekka, if paint on the body is solid, and in no danger of delaminating, or reacting poorly with an epoxy primer, see no reason to go to bare metal either. I am sure we will get some reactions from some on this.

A lot of paint shops do not want to guarantee their work over substrates other than bare metal, and there own particular product line, so understandable.

[dezeldoc]

The best and least destructive is to have it soda blasted. no warpage, does not harm rubber,glass,chrome only takes off the paint and it can be done layer by layer...also will not hurt fiberglass. grinders will make heat and warp as bad as a bad sandblast job in the wrong hands and sometimes the right hands also.

[drillmastertommy]

Those disks are awesome, they even eat rust out of pitted metal. I like to use a combination of clean n strip disks and chemical paint stripper whenever I take something down to bare metal.

I used the black discs to strip my entire truck and they were great! I got through a few, edges and angles wear them more quickly and it goes without saying you shouldn't work the same area for too long to avoid the warping heat. They strip non metal material so quickly that you don't need to hang around.

 

I would have liked to have the truck media blasted but between that and the discs there is a vast price gap!

[falconvan]

I think it's preference; I had my 48 Plymouth sand blasted and the little AMG stepvan I built a few years ago I did with a DA and a roll of 80 grit; along with an angle grinder and some 50 grit Roloc discs for tighter places. Both worked fine; one cost more; one was more labor on my part. All my projects go to bare metal unless Im just doing a quickie repaint for someone who wants it done on a tight budget. Too many unknows can hide under an old paintjob.

[chopt50wgn]

There are numerous ways to remove paint and everyone here has good ideas.

But if you decide to go the soda blasteing  which does work very well, most paint companies will not guarantee their paint over  soda blasted metal. Soda blasting leaves a residue that is very hard to remove and if it is not removed, everything from primer to topcaots can be jeopardized.

[52b3b Joe]

I've used everything from wire wheels, to a grinder with 80 grit, to a DA, to sand blasting and even an electric orbital sander. In my experience, an 8" DA with 40 grit and sand blasting are the best to get to bare metal. As far as going to bare metal, it comes down to what quality of work you want the finish product to be. On daily drivers, and on "driver" quality cars I've messed around with, I paint over the exiting. I have had no problem with that. The only car I've taken all the way down is my truck because I had it so far apart I couldn't justify not spending a weekend to sand blast it all. I'm happy I did. Its just a matter of personal preference and nothing more, unless the paint is in very poor shape. 

[grassfiddler]

It's all a matter of preference as to how you strip the paint off your car. I grew up working with my Dad who is a body man by trade. We painted countless cars just by sanding the old paint and reshooting on top of the old paint without any issues later on. With that being said we also at times had to strip body panels down to bare metal due to surface rust and old flaking paint that couldn't be sanded and painted over. We used a varity of methods for this that included 60 to 80 grit sandpaper on a DA sander, wire wheels on an angel grinder, a 9 inch grinder with 80 to 100 grit disk, sand blasting, and aircraft paint remover. All methods work well but have limitations as well as pro's and con's. For me it all depends on how many layers of paint, primer and rust that I need to remove. If the paint is thin, with or without surface rust, I would use a DA sander with 80 to 100 grit paper. Keep the sander flat and moving to prevent uneven sanding, gouging into the metal, and to avoid excessive heat. If the area to be stripped is rusty with some rust holes I would use a grinder 4 1/2" or 9" with 80 grit. Same princapal with the angel grinder keep it moving. If there are a lot of layers of paint to remove then I would turn to something like sand blasting or aircraft paint remover/stripper. I found this method to be easier on my hands, back, arms and shoulders instead of a grinder or sander when there are mulitple layers to remove. The stripper is a matter of applying it with a brush, letting it set, when the paint bubbles up scrape with a putty knife. Repeat as neccessary until all the paint is gone.

   I also like the wire wheel disks for the 4 1/2" angel grinder. I have used the brass ones with good success although they don't last long. They were good at removing paint without gouging the metal.

   With any method, the main things to consider are the amount of time needed to do the job right and your budget. Also consider the amount of time it will take once the metal is stripped to the time it will take to get the car in primer and then to the paint shop. To much time inbetween will lead to paint failure later on. With any method the metal needs to be clean before the first bit of primer is applied. Any dust, dirt, grease, oil, paint stripper, etc left on the car will cause problems later on.

   

Just a few tips:

    Make sure that you don't build excessive heat in the metal as that can cause warpage, take your time and pay attention to what your doing. If using a sander or       grinder, we always would sand/grind a couple of passes, take the tool off the metal and look to see what was just done, then reapply tool for a few passes, then recheck work. It saved us from doing damage that would we would have to fix and taking more time to get the job done. Keep the tool moving not spending to much time in one area.

   Also remember that with grinding or with heavy grit sandpaper, you scratch the metal much deeper than with lighter grits such as 220 or 320. So becareful with the heavier grits because the deeper the sanding marks the more sanding that has to be done to sand them out. Same applies to the wire brush method.

   The paint remover/stripper is messy. Be prepared for a lot of clean up, where rubber gloves, and a resperator.

    And with any method be sure to protect your eyes with saftey glasses, goggles,or a grinding shield, where hearing protection such as ear plugs or muffs, and a N95 dust mask when grinding or sanding.

[dezeldoc]

Wrong! it is a totally clean surface when finished. Walnut shells is the bad one to use it leaves oil from the shells embedded into the metal witch is hard to remove.

There are numerous ways to remove paint and everyone here has good ideas.

But if you decide to go the soda blasteing  which does work very well, most paint companies will not guarantee their paint over  soda blasted metal. Soda blasting leaves a residue that is very hard to remove and if it is not removed, everything from primer to topcaots can be jeopardized.

[Plymouthy Adams]

for certain, for everyone that likes a particular method there are those who don't......for every method there are steps need be done an those that again say they do not need the after blast steps performed..each can chose what they like that soothes their own ear or methods and gives them a warm fuzzy..,..if nothing else ones needs to read a few articles and evualate for themselves what they may or may not think is appropriate...for me....I think any blasting of any media used has an after action wash and protection step that should be taken...like everyone I have my method..it has proven itself effective over the 20+ years to me..

 

for those in favor of Soda..here is an article that may be worth reading...posting for your consideration only..I have no interest/concern either way...

 

 

http://atozsodablasting.com/AfterBlastRetail2.htm

[Uncle-Pekka]

I agree Pekka, if paint on the body is solid, and in no danger of delaminating, or reacting poorly with an epoxy primer, see no reason to go to bare metal either.

 

Sorry, I missed to underline the point of my method: None of the paint types used in professional car painting do NOT react with 2-component epoxy.

Epoxy uses different type of dilutions and hardening of the epoxy is a chemical reaction btw the two components rather that evaporation such as in acrylic paint.

Just the two qualities of epoxy make it a perfect sealer:

- it does not react with previous coat when wet

- it is very hard and tight thus does not let overcoat to react with the coats under the epoxy

 

I've tested epoxy with several different types and ages of paint and never got boiling of wrinking. 

 

Thus you can say I am swearing on Epoxy.

 

[dezeldoc]

It does not matter what you do to get to bare metal...all bare metal needs to be etched before any epoxy,primer or paint is laid down. Adhesion is the key to a good and lasting trouble free job. Remember the paint job is only as good as the prep.

[Don Jordan]

For all the cars I've done I've used Jasco. You brush it on and you can watch the paint boil off. Take a scraper and it just comes right off.