TopGunn

I've read a boatload of discussions on using Captain Lee or Citrus Strip to remove paint. I've run across aseveral threads that says after 84 you can't use either of these on SMC. Apparently in 84 the SMC material was changed??
In any event, I'm stripping my 75 that has a variety of coatings all the same color but some places have 1 coat (original) and others have two with several layers of clear.
I'm using a razor blade but it seems to only take it down to the gray primer so I thought I'd sand that...I hope! That works pretty well in open areas and flat surfaces but what about on curved surfaces and near the wheel. Can I safely use Chemical Strippers to get all this stuff off as long as I clean it well with water??
I've read that Captain Lee's is not soluble in water; if not water than what should I use........Alcohol???

This is a 75 car that is SMC.............anyone with real world experiences with SMC cars that has used this stuff?

I did my valence about 2 years ago and used an aircraft stripper then washed the heck out of it with water and it seems fine. I have no intentions on using aircraft stripper now but that stuff is pretty harsh and it didn't seem to cause any problems that time.

Thanks

zwede

On my '71 (71 had some SMC panels from the factory) we used aircraft stripper on the entire car. It will not take the factory lacquer primer off. For that we used "scotchbrite" (3M brown scuff pad) and plenty of lacquer thinner. Some on the forum say this will lead to problems, but we didn't have any problems with this. The key is to give the panels time to thoroughly dry. Minimum of 24 hours, preferably in the sun.

TopGunn

Well that's encouraging, some of these posts seemed to emply SMC was pretty sensitive to chemicals. In many areas I seem to have several layers of clear, then gray primer over another coat of paint. After I razor blade the clear and the top coat of color off there looks to be a primer coat over the original paint. Man is that layer of primer tough!
Have you ever tried a heat gun?

DUB

The heat gun will not remove that gray primer layer. It will work to aid in getting the paint off....but you have to be careful not to get it way to hot.

Chemical stripper will work...like zwede mentioned. I use it all the time and have had no problems...and I have been using it for 20+ years.

DO NOT FORGET.....
Use good gloves that resist the chemical in the stripper (methylene chloride). Make sure that you are out of direct sunlight when applying the stripper. Make sure that you have good air movement in your work area and that there are no items in the shop that can produce a spark while using the lacquer thinner..when you are scrubbing the paint/primer off and wiping the panels down afterwards to make sure that they are clean..
"DUB"

TopGunn

Hi Dub, Thanks for the info. Yeah that darn heat gun gets too hot for me to control well, I got a pretty gooey mess in front of the blade and was really scared I was getting it too hot so I stopped.
It's supposed to be warm here this week so maybe I'll take an afternoon off from work and open the garage doors and see how I do. Boy I wish it would have come off better with the razor blade, this is going to be messy.

DUB

So you do not get overwhelmed and/or frustrated...work small area at a time. This is so you can control the removal of the srtipper and the clean-up as you go along. It is a messy job...but can be made to be not so much of a disaster area. Working a small area at a time will also allow you to see progress...much faster than trying to do a whole panel and not get it stripped completely....and end up with a mess and a panel that is not completely stripped.

I do an area about the size of one sguare foot...until I see how the stripper is working and how much stripper I actually need to apply to remove what I am trying to remove. Thin coatings that take very little stripper to remove I will do a larger area due to the stripper and primer I wipe off is not a lot and is easily controllable.....thicker coatings that take more stipper to remove...I do smaller areas so I can control the waste and clean-up....and even sometimes have to re-apply the stripper due to the thickness of paint.

"DUB"

TopGunn

Thanks

I tried a test on the cover to the gas cap with some CitriStrip. Man is it slow, took 3 hours and three applications. I also covered it with plastic to stop the evaporation. I'm going to pick up some Klean Strip Aircraft Stripper for Fiberglass tomorrow and try another test.

When you do small areas like that, do you wash them completely after stripping before you go on to the next area or do you wait until you're done for the day and wash everything?

Bill

zwede

You wash the area when you're done, don't wait until the end of the day. The stripper will continue doing things until it is neutralized so you want to neutralize it as soon as the paint is gone.

TopGunn

Thanks. What do you use to neutralize the stripper......hot water followed by wiping with laquer thinner? That stops the reaction?

zwede

Either water or thinner stops the reaction. If the panel is clean you can just use water (cold water is fine). If you still have primer, or half dissolved paint on the panel a good thinner scrub is needed. Before you put anything onto the panel (filler, primer etc) be sure to give it a real good scrub (scuff pad) with water & dawn, then followed by clean water. Finally let it sit and dry for at least 24 hours.

zwede

Another thing: If you do wipe any of the panel with thinner, even if it's just a small spot, you need to wait 24 hours before putting anything onto it. A common mistake is to wipe it with thinner and then immediately shooting primer. Not a good idea.

TopGunn

Got it. Thanks for the advice!

Bill

DUB

I personally use only lacquer thinner to wash down the panels with after stripping. I do not like to use water OR water with any soap product. I have a fear of the residue of the soap getting into the structure of the fiberglass/SMC where it has been damaged. For me that is just one more thing to worry about...so that is why I use only lacquer thinner. I know many people believe in it...but I can not go along with it...personally. Plus with 20 + years of using only lacquer thinner and never having a problem...it is hard for me to change because with my luck...something would go wrong. Like mentioned...just give the fiberglass/SMC time to dry out if using lacquer thinner before you apply anything on top of it.
"DUB"

TopGunn

I appreciate the advice, thanks very much. I picked up the aircraft stripper today, should be able to make a mess by Saturday morning I'm sure I'll have some more questions.

Bill

DUB

OOOPS...do not forget to have a face shield or good eye protection.
"DUB"

1snake

Oh my, you do the same as I do, yet the "pros " say you will ruin the body if you use lac. thinner on it. Here's a recent thread on the subject. http://forums.corvetteforum.com/pain...dy-filler.html

I wonder, if lac. thinner ruins fiberglass, how did GM get by with spraying it on their cars for so many decades.

TopGunn

I think I'll stick with the razor blade method. I used some stripper on the underside of the front end as a test. What a freaken mess! It looks like I can get 80% of the paint off with a razor blade down to the gray primer so I think I'll let the paint shop bring it down the rest of the way with a sander. If he's going to stand behind his paint job, I'll let him prep the surface with methods he's comfortable with and I'll stay away from putting chemicals on the car just in case.

zwede

Unless this painter has done plenty of Corvettes before, this is a bad idea. I've seen the result of a DA sander on a Corvette and it wasn't pretty.

DUB

Getting 80% off down to the primer with the razor blade method sounds good...in theory...but it is that last 20% that will... and often does.... make or break the quality of a paint job.

Trusting "them" to finish out your car is entirely up to you. But it is often the "nooks and crannies" that come back and haunt the owner if the paint shop does not correctly remove paint from these areas....and unless they know what they are doing...it can create more problems than you can imagine....especially if using air sanders on a panel for speed of preparation.

Best of luck in getting your car repainted.

"DUB"

TopGunn

Well, based on the advice of others and doing some more thinking about all this, I decided to strip the car with a razor blade as much as possible to ease in the sanding procedure and with the idea that I'd stop whenever it looked like I was doing damage to the car with the blade.

My car has been painted a couple of times in various places for some reasons, I've never found any body damage. To my surprise the top layers of clear (many) along with at least one coat of paint came off very easily for the most part, I think I had the whole car done in two days doing it part time. I did the back deck in about 15 minutes.

Under the top layer of paint, most of the car had a layer of some kind of gray epoxy primer over the original paint that was stuck pretty good; It would not come off with a razor blade alone. I used a temperature controlled heat gun to preheat the area and generally it peeled right off right down to the SMC. The only places it wouldn't come off were areas that had a coating of some kind of body filler where my rear bumper (Ecklers) had been blended in and on top of the seams over the epoxy or whatever is used there. I left those places the way they are to be sanded down.
Here's a shot of the epoxy after the paint was removed.



The hood had no epoxy and it looked like it was painted right over the SMC and the paint was stuck on there like glue, it wouldn't come off without damage. But........a little hot air from the heat gun and it peeled off like butter...amazing. No digs or gouges at all. The surface was as smooth as new in most places. Here's a shot of the hood after about an hours work.



What little thickness of material in those hard to remove areas I think can be removed by sanding without any loss of contours.

I was really impressed with how easy the removal process is made when using the heat gun. Make sure you use one that you can regulate the heat so you don't get things too hot, you can do damage with one if you're not careful. I set mine about 50% of the scale and kept it moving all the time.
Still a ways to go but I'm getting there...........