CRG Discussion Forum

Camaro Research Group Discussion => Restoration => Topic started by: timmorgan on December 31, 2009, 03:38:45 AM

Title: Remove rust or sheet metal?
Post by: timmorgan on December 31, 2009, 03:38:45 AM
O.K. guys, I'm new to the restoration world and my head is full of questions. I'm trying to decide if I should replace sheet metal ( hood, top, trunk, fenders and quarters ) that are covered in surface rust that is deep enough to cause pitting. My 69 is an original x44 and I intend to keep it that way. It has been sitting in a barn for the last 17 years and surprisingly the under side is in great shape. The floor pans and trunk pan are good. Everyone has been giving lots of different advice, but this could be the biggest deciding factor in what I do with the car. Please help! ???
Title: Re: Remove rust or sheet metal?
Post by: Sauron327 on December 31, 2009, 09:32:29 AM
A thorough inspection is required for proper assessment. Unseen, pitting indicates thin metal. And panels also rust from inside and at pinchwelds, lower fenders, window channels, etc. Failure is usually immenent in previously repaired areas, if any are present.
Title: Re: Remove rust or sheet metal?
Post by: tmodel66 on December 31, 2009, 01:02:05 PM
I have been doing body work for 30 years. If the rust does not go all way thru I would not replace  anything. Replacement parts just don't have the quality as factory.  As far rust that is all way thru I put a patch panel in if at all possible. A hole the size of a beer can can be patched real easy and you won't have to fight that aftermarket fender for line up. I will not replace a whole quarter just for rust thru in lower half where these cars are notorious to rust out. Put a panel piece in it and leave the integrity of the original body in place. However I would replace any structural pieces that have rusted thru.  BTW  cut out and replace 1 piece at a time then move on to the next place. This way you don't have to worry too much about body twist.
Hope this don't confuse you and good luck with your project.

Daniel


Title: Re: Remove rust or sheet metal?
Post by: jmcbeth on January 06, 2010, 07:56:36 PM
I agree completely with Daniel. Replacement panels are notoriously poor fits and can be easily spotted by judges at nationals. If you can save the existing panels, take that route.
Title: Re: Remove rust or sheet metal?
Post by: Buddy on January 06, 2010, 08:11:22 PM
If at all possible save the original panels. They are heavier than the replacements so even with a little thinning they might still be thicker than replacements. Replacements can be identified a mile away.

Buddy 8)
Title: Re: Remove rust or sheet metal?
Post by: Sauron327 on January 06, 2010, 08:19:36 PM
Or.....If the pitting is excessive buy NOS or excellent used. Sight unseen, hard to tell.
Title: Re: Remove rust or sheet metal?
Post by: timmorgan on January 07, 2010, 01:27:37 AM
Thanks guys, I'll try to keep the originals. I've also been told about  alot of different methods of removal and treaments to prevent the rust from coming back. I have heard horror stories of rust returning to ruin a nice paint job. What do you suggest---sand blasting is my thought?
Title: Re: Remove rust or sheet metal?
Post by: tmodel66 on January 07, 2010, 01:25:58 PM
My personal choice would be to have the car dipped if you have a place close enough to do it.  But here are a few options I use if you don't want to go that route.  First I would either soda blast or strip with airplane stipper on the outside of the car. The places that are rusted allway thru can be sandblasted to get good metal so your patch will go in to good metal. On inside of fenders and and parts that are out of sight use the sand blast.  The trick to sandblast is never shoot straight on. This heats the metal too much and will distort it. Always shoot at an angle and DO NOT hold it on tough spots just for the sake of cleaning. Keep it moving all the time and if you have a stubborn spot just move on and come back to it.  Also blast inside of all panels after you weld in patch panels because the heat and weld surface will leave slag on inside and you will losse adhesion of any primer or paint and this in time will let the rust return.
   

    Daniel
Title: Re: Remove rust or sheet metal?
Post by: BILL69 on January 07, 2010, 04:09:15 PM
Your budget will have to be the determining factor.    Will you be doing this work yourself,  or paying the body shop rate?   I agree the original panels will be a better fit but the cost of repairing them will be expensive.   I was faced with the same question a few years ago on a car I was restoring.  My body repair man is a good friend so we sat down after disassembling the car and determined which parts where economically worth repairing.   I ended up installing new quarters and hood but repairing the front fenders.  The car looked great and I was not bankrupt.   Good luck.   
Title: Re: Remove rust or sheet metal?
Post by: timmorgan on January 08, 2010, 02:46:22 AM
Thanks for the info! None of the sheet metal is rusted completly through, just heavy surface rust. Will soda blasting remove rust? Someone told me it only removes paint. I don't know anywhere to have it dipped, sand blasting or soda blasting are my options right now. I'll try to post some pics.

Thanks!
Title: Re: Remove rust or sheet metal?
Post by: tmodel66 on January 08, 2010, 03:11:02 AM
Yes soda blast will remove surface rust. It does take a little extra time but I believe you will be pleased with the results.  I don't know what your inside surfaces look like but if you have that much rust on the outside I can imagine. I would still sandblast inside.
Title: Re: Remove rust or sheet metal?
Post by: timmorgan on January 08, 2010, 11:25:47 PM
The inside has only a few small spots, but I'm doing inside and out.
Title: Re: Remove rust or sheet metal?
Post by: Sauron327 on January 09, 2010, 12:09:15 AM
I've never heard soda good for anything besides removing paint. And it needs to be neutralized to prevent paint failure. And dipping opens up other potential problems. We've sandblasted for decades, obviously not flat panels and never had problems. DA with 80 and epoxy primer prior to proceeding with work.
Title: Re: Remove rust or sheet metal?
Post by: tmodel66 on January 09, 2010, 12:43:59 AM
I have never heard of neutralizing anything after you sodablast.  The only thing I do is DA with 180 and shoot the primer on it.  Never had any problems.  Now I have had to neutralize the soda before disposal because of the contents after use.
Title: Re: Remove rust or sheet metal?
Post by: Sauron327 on January 09, 2010, 02:38:13 AM
I've never had the need to sodablast and based on others' claims I prefer not to enter another possibility of failure into the equation. If it works for someone then that's great. This statement among others is a reason I do not do it, it was written by RamAirDave:

"Had one car soda blasted. Wouldn't consider it a 2nd time, and I don't know anyone that has.

Soda is a very soft media, needs a lot of psi, around 120 is what the local guy blasts at (he's looking to get out of it, go figure... ). There is a fine line. Some have been using it for many years and have it figured out. But too much psi and it embeds into the metal.

Try sticking a piece of masking tape to something that has been soda blasted. After you pick the piece of tape off of the floor, realize that there is an adhesion issue that you have to address. There are washes/solutions to clean it (tried them), but you better get EVERY SINGLE NOOK, EVERY SINGLE CRANNY. Three times.

Sure, you get clean, smooth metal, but it creates another issue that sets you back. I've heard the sales pitch years ago and I bought into it. I now know better.

With other media, if you don't get 100% of the media out, you get trash in the paint. Sucks, of course. But with soda, if you don't, you have paint chips/flakes on the ground.

And if there are issues down the road after the car is painted, some paint mfgs won't stand behind/warranty a qualified painter if they know the car was soda'd." 
Title: Re: Remove rust or sheet metal?
Post by: ChrisM on January 09, 2010, 04:38:19 PM
The aggregrate on sand paper is aluminium oxide.  If you bast with aluminium oxide it avoids the problem of paint not sticking.  You still have media that needs to be shop vac out of the car, but problem solved.  Just keep the gun moving and shoot at an angle so you don't burn a hole in or warp the metal.
Title: Re: Remove rust or sheet metal?
Post by: timmorgan on January 10, 2010, 03:39:39 AM
I think I'll stay crear of something so controversal. Sandblasting sounds to be the preffered method. What about some feedback on rust encapsulators or rust converters.
Title: Re: Remove rust or sheet metal?
Post by: sixt9x33rs on January 11, 2010, 03:28:03 AM
I think I'll stay crear of something so controversal. Sandblasting sounds to be the preffered method. What about some feedback on rust encapsulators or rust converters.

I have had great luck with evap o rust.
I used POR 15 on my Corvette frame with great luck. DP 90 on my Z frame.