Ok, I've read through the bodywork section here and Shop Talk Forums and came up with alot of different opinions on metal work and filler.
From what Ive concluded you can remove dents using the hammer & dollie with minimal body filler and by using a shrink disc even less to no body filler.
Then going on to filler, some state that it should be applied to bare metal and others say it should be primed first. Which is really the best method? before of after? Some also state that etching prime should only be shot on bare metal and not be shot over the filler is this true?
2 final questions left please bare with me,
Can paint be removed using a wire wheel on a grinder or does it cause to much heat? I've read people mention using scotchbrite pads I assume this would be similiar?
Lastly its stated that a shrink disc only works the highs and by heating the metal it shrinks the metal back to its original "memory" position. Can this be used in reverse? Meaning if you can work a low from the back side (making it a high)?
Thanks guys, just trying to clarify things not beat a dead horse!
Metalworking
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All_talk
- Posts: 371
- Joined: Wed Jun 19, 2002 12:01 am
Hi imflynt
I gave some opinions on metalwork, filler and primer recently in another post, here?s a link (saves me from typing):
http://shoptalkforums.com/viewtopic.php?t=53819
Wire wheels can actually transfer metal from the stainless steel (or brass) wires to the sheet metal, which may cause finish adhesion problems. That said, I have used one to strip to bare metal but always sanded (DA) the metal before refinishing, no trouble so far.
I can't comment on the shrinking disc as I haven?t used one, but it?s on my list of tools to buy before my next project.
Gary
I gave some opinions on metalwork, filler and primer recently in another post, here?s a link (saves me from typing):
http://shoptalkforums.com/viewtopic.php?t=53819
Wire wheels can actually transfer metal from the stainless steel (or brass) wires to the sheet metal, which may cause finish adhesion problems. That said, I have used one to strip to bare metal but always sanded (DA) the metal before refinishing, no trouble so far.
I can't comment on the shrinking disc as I haven?t used one, but it?s on my list of tools to buy before my next project.
Gary
Last edited by All_talk on Mon Aug 25, 2003 12:59 pm, edited 1 time in total.
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Air-Cooled Head
- Posts: 1684
- Joined: Fri Nov 23, 2001 12:01 am
Yes, if you can work the backside to raise a low spot, the shrinking disc can be used. However, with proper bumping technique, it shouldn't be necessary. If your plan is access the backside to beat a low spot into a high spot on the front, you're in for lots-o-work, as this will require a good deal of exprtise to smooth.
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SteveE
- Posts: 281
- Joined: Wed Dec 05, 2001 12:01 am
If your intent is to remove large sections of paint, like on a complete body panel or the entire car, I would suggest using a chemical paint stripper first to remove most if not all of the paint and then using a wire wheel or sander to remove the remainder. Just be sure to wear rubber gloves, protective googles, and old clothes, and don't do it in an enclosed area (fumes), do it outside where you can use a hose to wash things down. Use masking tape and multiple layers of paper to protect parts you don't want the stripper to attack. Use cheap natural bristle brushes to apply the stripper, and disposable plastic scrappers and old rags to scrape/wipe off the stripper and paint. If there are very thick or multiple layers of paint it may take two or more applications of the stripper to get it all off. Be aware that stripper will also soften/remove most body fillers. A bit of advice, go easy when using the wire wheel, too much pressure can cut deep scratches into the metal (ask me how I know 
). Better yet there are abrasive impregnated plastic "wire wheels", that are a lot easier on the metal, I've used them with great success. They work great for things like rain gutters vent louvers, and door hinges,anywhere the DA sander can't get to easily. 
Whatever you do, be sure to wear googles and a respirator or dust mask when using the wire wheels or sander, the paint/metal dust is very bad for your eyes and lungs. 
). Better yet there are abrasive impregnated plastic "wire wheels", that are a lot easier on the metal, I've used them with great success. They work great for things like rain gutters vent louvers, and door hinges,anywhere the DA sander can't get to easily. Whatever you do, be sure to wear googles and a respirator or dust mask when using the wire wheels or sander, the paint/metal dust is very bad for your eyes and lungs. -
John Kelly
- Posts: 664
- Joined: Sun Mar 18, 2001 12:01 am
Aircooled head wrote:
"Yes, if you can work the backside to raise a low spot, the shrinking disc can be used. However, with proper bumping technique, it shouldn't be necessary. If your plan is access the backside to beat a low spot into a high spot on the front, you're in for lots-o-work, as this will require a good deal of exprtise to smooth."
The shrinking disc makes the smoothing easier. It is so simple that you can use the wrong techniques with hammer and dolly and still get a perfect finish. I'm confident that I could repair a simple dent with just a ballpeen hammer and a shrinking disc, although of course a little hammer and dolly work would be preferable. The disc takes the guess work out of where to do what by highlighting the highs and lows. Bumping out, and hammer and dolly work does increase the stretch just slightly, and the disc simply shrinks these areas while relaxing the tensions in the metal. It takes an expert to come close to the same quality using hammer and dolly and a torch. Even using a worn out scotchbrite pad on your 7" grinder instead of a shrinking disc is a superior way to go. I will never use a torch to shrink a body panel again unless I can't reach it with a disc. I've made a smaller disc from a stainless pitcher for getting into reverse areas, and may make one with a high crown as well.
John www.ghiaspecialties.com
"Yes, if you can work the backside to raise a low spot, the shrinking disc can be used. However, with proper bumping technique, it shouldn't be necessary. If your plan is access the backside to beat a low spot into a high spot on the front, you're in for lots-o-work, as this will require a good deal of exprtise to smooth."
The shrinking disc makes the smoothing easier. It is so simple that you can use the wrong techniques with hammer and dolly and still get a perfect finish. I'm confident that I could repair a simple dent with just a ballpeen hammer and a shrinking disc, although of course a little hammer and dolly work would be preferable. The disc takes the guess work out of where to do what by highlighting the highs and lows. Bumping out, and hammer and dolly work does increase the stretch just slightly, and the disc simply shrinks these areas while relaxing the tensions in the metal. It takes an expert to come close to the same quality using hammer and dolly and a torch. Even using a worn out scotchbrite pad on your 7" grinder instead of a shrinking disc is a superior way to go. I will never use a torch to shrink a body panel again unless I can't reach it with a disc. I've made a smaller disc from a stainless pitcher for getting into reverse areas, and may make one with a high crown as well.
John www.ghiaspecialties.com