Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/index.php)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/forumdisplay.php?f=8)
-   -   question about things learned while stripping paint... (http://forums.pelicanparts.com/showthread.php?t=258940)

randywebb 01-06-2006 08:43 PM

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.

brittbolen 01-06-2006 08:45 PM

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

brittbolen 01-06-2006 08:47 PM

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

Britt

toolman 01-07-2006 11:53 AM

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

Zeke 01-07-2006 01:34 PM

Quote:

Originally posted by brittbolen
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...


Britt

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.

AtomicDog 01-07-2006 02:22 PM

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

brittbolen 01-07-2006 02:32 PM

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

Britt

Zeke 01-07-2006 02:52 PM

Quote:

Originally posted by AtomicDog
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

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.

randywebb 01-07-2006 02:57 PM

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....

Dixie 01-07-2006 03:09 PM

Quote:

I don't know why anyone would attempt this without the proper tools.
Start over at page one. He IS using the proper tool...

AtomicDog 01-07-2006 05:25 PM

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

brittbolen 01-07-2006 06:34 PM

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

Zeke 01-07-2006 06:51 PM

Quote:

Originally posted by brittbolen

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?

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.


Quote:

Britt, who knows very very little
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. ;)

mcholar911 01-07-2006 07:00 PM

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!

turborat 01-07-2006 07:12 PM

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.

brittbolen 01-07-2006 07:27 PM

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

Brit

9dreizig 01-08-2006 05:24 AM

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

brittbolen 01-08-2006 09:30 PM

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

davidppp 01-09-2006 03:31 AM

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

brittbolen 01-13-2006 07:08 AM

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


All times are GMT -8. The time now is 06:45 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.