question about things learned while stripping paint...
 

So I'm in the process of stripping my 911 so I can get it repainted. I'm using the razor blade method (using this tool from sears) and I've started with the passenger door.

I thought my car hadn't been repainted but this door definitly has, the top layer of paint is very easy to scrape off. The odd thing is that i'm seeing spots with a brown layer between the 2 layers of white.

Why would they have only primed some areas? When I scape down through the brown layer I don't see any difference in the metal surface, it's just like the areas without the primer (well the primer does make the scraping process harder...)

Britt

Primer-surfacer, most likely there were some minor imperfections there that they leveled out and used a couple coats to smooth out sanding scratches.

ahh, so lets say the door was keyed, they would spray primer over the scrapes, and then sand that down to match the existing paint, then paint over the whole door?

B

I would worry less about the brown layer and more about your sanity after stripping paint with a razor blade!

If you are serious about removing the stuff you need to bite the bullet and either start using a decent aircraft grade chemical stripper or get it media blasted. Don't be scared of making a mess- you will. That's half the 'fun'.

Good luck!

I'll second that.

sjd

ROTFLMAO!! :D

Sorry but I was thinking the same thing. I have never heard of, or even considered stripping a car with a razor blade.

Well, now you’ve learned something new. :cool: I've stripped cars with a razor. Although it's a bit tedious, it works amazingly well. (Especially if it’s a fiberglass car.) It provides a lot of control over the stripping process. Plus, you don't have the cloud of dust you'd have if you used a DA, and you don't have to worry about a chemical stripper getting where you don't want it.

Yes, you understand perfectly. Although hopefully they feathered the scrapes first. Otherwise the scarpe marks would "telegraph" through the repaint in a couple months.

I know someone that had a 911 where the clear coat was in bad shape so they stripped the clear off with a razor and then repainted - car looked amazing

I did an entire VW beetle with that same kind of tool.
Simple aerosol gasket remover was enough to completely lift the paint and almost no force at all was needed to get right to the bare metal.

I have used the razorblade method, It works great on unmolested cars, but it doesnt work so good on cars that have had extensive body work done.

I doubted the razor blade method as well... I thought it was a giant hoax perpetrated by my mechanic and john walker... then i got a better blade holder, and found the magic touch...

With the proper angle and light touch it's one swipe down to metal. I like this method, no nasty chemical burns, no toxic dust clouds, $5 in tools. Just make sure you wear the safety goggles, when those blades break it's not fun!

Britt

Progress so far...

http://eludicate.com/~bolen/911E/pho...DSCN8059_t.jpg

I need to get that other fender off so I can get the front bumper off, but I don't think that hose between the gas tank and the filler neck has ever moved, and i'm not sure how i'll get that off!

Britt

I'm a fan of the razorblade method. done quite a few cars this way. The whole car!

I build and repair guitars for a living and after 30 years, I am done with slovents!

One thing to speed up the razorblade process is a heat gun.

fast fast fast

Is that bondo in a rust hole in the lower, front area of the door? If so, don't be surprised to find many peculiar things.

Uh, Britt?
You are a Great Man - with far greater capacity for patience than I. I've got your Nobel Prize nomination going in another window here, after you accept the prize I suggest you negotiate peace in the Middle East. If anyone can do it...you're the man. What a task!!

Hi,

Try using a propane or Map gas torch .. with one of those clip on flame defectors that come with a propane torch. Just heat up the paint till the surface just starts to bubble .. and you can just use a paint scraper
and the paint will peel off .. right down to the base factory primer.
minimal sanding .. and you can just sweep up the paint curls.Beats the hell out of D/A sanding a car down to metal , and the masive amounts of dust everywhere !
Dont use too much heat , and move around a bit on a panel , it wont get hot enough to warp the metal..your just softening the paint and bondo

Make sure you use in a well ventilated area, and use a mask .. you dont want to breath in the fumes.I stripped several cars like that and it worked great for me

Take care - Joe -

You guys talking about heat scare me. Don't bring me a door that has had too much heat and ask if I can straighten it out.

Seriously, sandblasting heats the metal enough to work harden the metal and distort it as well. You never ever sandblast a large, flat, thin piece. I know, he didn't say he was. I'm just pointing out that one has to be careful when doing bodywork. My personal recommendation is to not use heat on your door. Maybe hard to get to ribbed panels, but not flat exterior surfaces. YMMV with the amount of heat.

This will sound like a silly question... what does bondo look like when scraping a car? Is bondo this very dry brown stuff i'm finding in spots on the door? I had thought it was primer, but then i discovered it wasn't everywhere...

I scraped the bottom of the door down to metal, and there are these black spots, but nothing rotten all the way through...

No bondo in the quarter panel yet.

I'm going to avoid heat, don't want to warp anything. Only heating i'm doing is using a hair dryer to make the turn signal plugs push out of the body much easier.

I'm going to media blast the bumpers, fenders, and possibly the hood and decklid. Not sure on them, i don't want beads falling out of the deck lid and hood for the next 5 years...

Britt

My main concern with the razor blade method is the nicks in the metal that i'm getting from the corner of the blade when it catches... I think it's nothing primer and sanding wouldn't fix...

Britt

bondo looks white - at least that I've seen. could be brown -- don't worry it will be very obvious that whatever it is is NOT metal when you are doing it.

Here are the 2 rust spots in the lower front corner of the door. All the bondo has been scraped away, leaving these spots, which are not much bigger then the tip of my pinky finger

http://forums.pelicanparts.com/uploa...1136612491.jpg
http://forums.pelicanparts.com/uploa...1136612508.jpg

And the progress through today, no scraping tonight. Tomorrow I'll do more disassembly, fender off, lights out, door handles off.

http://forums.pelicanparts.com/uploa...1136612521.jpg

Britt

The bondo, seems very thin, and under it i can't see any obvious dents...

Britt

I don't know why anyone would attempt this without the proper tools.

Body fillers can be a number of different colors and shades. The most common are pinkish and blue. Reddish brown is a popular primer. Bondo (body filler) dissolves somewhat with paint stripper, softens with pretty high heat, and sands like wood.

Funny, I would have guessed that the brown stuff is glazing compound. It goes on REALLY thin, but hardens like iron compared to bondo. Really does the job of filling scratches and pinholes though.

Chris

it could be glazing compound, it is a much harder to remove than the paint, MUCH harder.

Britt

Good point. Britt, you've got to get that rusty metal out of the door or you will have bubbles in your new paint in time. Not that much time, either.

I was just looking at one of my cars (not a p-car) that I painted in 2002. It has bubbles in some of the spots I repaired. I come from the fiberglass side of bodywork (Corvettes) and part making, so at the time, I didn't take enough precaution. I can't emphasize enough how persistent rust is. It won't stop if any trace is left. It truly is a cancer.

Never assume that a PO did work correctly... who knows what they filled holes with -- could by Play-dough, Silly Putty, Plastic Wood, sawdust mixed with Elmer's glue....

Start over at page one. He IS using the proper tool...

Make sure that you wipe down the panels, particularly the formerly rusty areas with a phosphoric acid rust converter, such as Ospho. When you think you've made it to bare metal, realize that at a microscopic level, there's still rust. The Ospho converts the red gamma hematite (rust) to iron phosphate. Only then can you be sure that it will not come back...

Just make sure to SCRUB the residue off the panel when you wash for paint prep. Although the product claims that the post-treated surface improves paint adhesion, it's a lie. The primer sticks to it, but because the stuff has the consistency of hard wax, the surface cannot be made smooth.

$2.00 worth of words to give $0.02 worth...

Chris

Chris, my mechanic has been advising me on how to do this, and also recommended Ospho. I picked up a bottle.

You're talking about the Ospho residue? I was told to spray it on, let it sit a few minutes and then wipe it off. The car might not get painted immediately, and certainly not by me, so i'm sure they'll be sanding it then...

Milt, do you think, from the photos, that a wire brushing and a treatment like ospho is good enough, or do i need to do something drastic like cut out the corner of the door? I guess it depends on what the inside of the door looks like, doesn't it?

thanks guys, this is all very helpful!

Britt, who knows very very little

You got it. Much of the work is done "behind the scenes." That was my problem, I didn't address the backside thoroughly enough. Anything that goes completely thru the panel has to be cut out, IMO.


Yeah, but you're here asking. That's an excellent way to achieve a great job. You've got dozens of capable advisers, but none looking over your shoulder. ;)

Looking back, I've tried a bunch of rust "treatments" POR-Ospho-etc. and never been able to truly kill the stuff. Rust never sleeps, the only sure, long term method is too cut it out, weld in a new piece, and start fresh. IMO. But that brings a whole new set of issues, especially if your not great with tig or mig, or straightening sheet metal. For the low dollar resto, baking powder blast, immediately seal with POR 15, and get some paint on it asap has worked on my old bikes pretty reliably, Good Luck!

I too prefer the razor blade method. Never done a complete car though. I round off the corners of the razor blade and this drastically reduces the "digs" into the metal.

sweet, i was thinking of trying to round off the corners of the blades!

Brit

Why not spend the $500 and have it media blasted ?? that's what the pros do..??

So I considered the media blasting option, and discussed it with my mechanic who's been helping me prep the car for paint, and, well, i wanted to do as much stuff myself as possible 1) to have something to do 2) save some money, and 3) and well, i'm not going to take the whole car apart, so I might have a lot of media rolling around for, well, forever...

Anyways progress is good, i'm probably 1/3 stripped at this point... found a little bondo in the bottom corner of the quarter, but nothing bad so far...

Britt

Hi there.

That door will need nothing less than a new lower portion.

The work involved in putting things right first time is far less then doing it twice.

Ask me how I know this!

Kind regards
David

a stripper's work is never done...
 

Progress through last night...

http://forums.pelicanparts.com/uploa...1137168290.jpg

Now there is some bondo here, kinda thick... should I scrape it all out, or leave it as a starting place for the body shop? You can see one spot where i scraped into it...

http://forums.pelicanparts.com/uploa...1137168353.jpg

Sometimes we get a little bit optimistic, you know, like when you see a longhood on ebay and you _believe_ the 'no rust' description, well I had my moment of extreme optimism...

And a word to the wise, don't bother trying that "no fumes, indoor safe" paint stripper crap... it couldn't strip WET paint. Now I'm left with a layer of paintless primer that won't budge with a razor blade...

Britt