Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 33

Thread: long-term rust protection of bare metal

  1. #21
    Join Date
    Mar 2010
    Location
    switzerland
    Posts
    1,595

    Default

    i would use zink paint (spay).

  2. #22
    Join Date
    Sep 2008
    Location
    Central Kentucky
    Posts
    2,713

    Default

    Quote Originally Posted by jdunmyer View Post
    You guys gave me a great idea: I'll have to sandblast the parts when it comes time for a final paint job.
    NO, DO NOT SANDBLAST BODY SHEETMETAL!!!!! A sandblaster will warp most sheetmetal body parts beyond any hope of repair! I don't mean "Aw s#!* now I am going to have to fix that", I mean toss it in the scrap and buy new parts kind of ruined. Some parts that are stiff and well supported like door posts and some firewalls may be blasted ok but fenders, hoods, trunk lids, etc will be instantly distorted way beyond any repair. Those sand particles act like millions of tiny peening hammers and will distort the surface of the metal due to the uneven stretching (and no, heat has absolutely nothing to do with it despite the common misconception so keeping the parts cool is futile!). While it can and has been done successfully the blast operator has to REALLY know his stuff and even then it's highly risky.

  3. #23
    Join Date
    Oct 2005
    Location
    Lower SE Michigan, USA
    Posts
    1,546

    Default

    NO, DO NOT SANDBLAST BODY SHEETMETAL!!!!! A sandblaster will warp most sheetmetal body parts beyond any hope of repair! I don't mean "Aw s#!* now I am going to have to fix that", I mean toss it in the scrap and buy new parts kind of ruined.
    Opps! I've heard that, but had forgotten. I'm used to thinking in terms of tractors, which have much more substantial sheetmetal.

  4. #24
    Join Date
    Sep 2008
    Location
    Central Kentucky
    Posts
    2,713

    Default

    Yep, I sandblast tractor parts all the time but I have warped a few items even there! My first experience with this was many years ago on a '56 Chevy trunk lid (the car wasn't all that old then! ), and because I didn't know any better at the time that thing was destroyed! Since then I have seen a lot of damage from doing this with the most heartbreaking being a 1966 GTO that a guy brought to the shop to see if we could "fix it", he was going to restore the car and had some guys sandblast it clean of all the paint and what little rust it had but it was pitiful to look at after they finished. Every single flat panel on that thing was distorted beyond repair, fenders, doors, hood, truck lid and even the roof was distorted and I mean DISTORTED! You would think those guys would have seen what they were doing and stopped but they didn't and there wasn't much left that could be used, the floor pans, door posts, firewall and inner fenders were about all that survived. There was nothing I could do with it so he left without even taking it off the trailer and I have no idea what eventually happened to it. I know another fella who did nearly as much damage to a 65 Mustang he had owned almost since it was new, he believed the old misconception that heat generated from the blasting was what did the damage (in reality sandblasted parts do not get hot however) so he had a water spray set up to keep the back of the panels wet and thus cool but that, as he found out, does not help! This one was pretty much the same situation as the GTO with the guy coming by the shop wanting someone to repair the damage but unlike the GTO he was doing his own work on it and stopped blasting when he saw what was happening, nothing on that one was ruined that couldn't easily be replaced. I have seen parts successfully sandblasted but it is extremely tricky to do, if the pressure is kept as low as practical while still removing the paint and the nozzle is held so that the sand stream hits at an angle instead of impacting directly then the peening effect is reduced but even that can still do damage.

    Soda blasting is safe but the little experience I have had with it is that while it will remove paint ok it doesn't do much for rust, but then maybe I just didn't have everything right. I only tried it once and with a cobbled together setup, it made such a mess in the shop that I never used it again.
    Last edited by radkins; 12-19-2016 at 02:25 PM.

  5. #25
    Join Date
    Jan 2006
    Posts
    411

    Default

    Quote Originally Posted by radkins View Post
    NO, DO NOT SANDBLAST BODY SHEETMETAL!!!!! A sandblaster will warp most sheetmetal body parts beyond any hope of repair!
    As is common for blanket statements, especially those with CAPS and lots of exclamation points, it ain't always so.

    I regularly sandblast body panels, and have yet to have any warp damage. My secret? Use a smallish consumer grade unit with a 5 horse compressor. No, I'm not going to go into the blasting business with this equipment, but it's served me well for years on many projects, including entire cars.

    Ed

    For just a little more, you can do it yourself!

  6. #26
    Join Date
    Sep 2008
    Location
    Central Kentucky
    Posts
    2,713

    Default

    Quote Originally Posted by ed_h View Post
    As is common for blanket statements, especially those with CAPS and lots of exclamation points, it ain't always so.

    As is common for folks who tend to flame others, ignore part of what was said to make your case, now go back and read what I said. I clearly said it can be done and I have seen it done and I too have even have done quite a few parts like you picture there, my point is in most cases of flat panels great harm is done and it's extremely easy to totally destroy FLAT PANEL POORLY BRACED sheetmetal like hoods, most fenders and door panels! Even when a person is well aware of the hazards and takes the proper precautions it's still very risky, and BTW I also pointed out that parts like you are showing there are usually safe to sandblast. What you are showing is not only heavier metal but is stiffer and well braced, unlike flat panels such as doors and hoods etc, pointing to a hood or door that has successfully done is also meaningless, I have been doing body work since 1971 and horror stories abound from folks who found out the hard way plus this very subject has been discussed at great lengths on some of the popular auto body forums.

  7. #27
    Join Date
    Jan 2006
    Posts
    411

    Default

    Quote Originally Posted by radkins View Post

    ...fenders, hoods, trunk lids, etc will be instantly distorted way beyond any repair.
    That's pretty graphic talk. Yet I've done quite a few with no bad results. As an operator, I don't think I "really know my stuff". I'm just this schmuck who, not knowing any better, sandblasts a lot of exterior car panels with pretty darn good results.

    Ed
    For just a little more, you can do it yourself!

  8. #28
    Join Date
    Dec 2007
    Location
    South Wales
    Posts
    6,043

    Default

    There's a firm down the road that does car body shells, apparently with shells, I think it's walnut shells but the guy said they have never used sand anyway, he called it "media" blasting, they had bags of crushed glass, some plastic stuff, black stuff I'm going to guess as emery, I had a bag of that off him, I use it in a gun but it's painfully slow as a paint remover, I have 2 gates to do, I haven't figured out how but I think a bigger compressor is needed than the home shop kind I've got, I'm told 14cfm min, I think it's going to be easier to get them done for me (though I resist that urge, whenever I do it costs me a bloody fortune, I'll never learn)
    Mark

  9. #29
    Join Date
    Aug 2004
    Location
    Sunny So Cal
    Posts
    3,458

    Default

    Quote Originally Posted by ed_h View Post
    That's pretty graphic talk. Yet I've done quite a few with no bad results. As an operator, I don't think I "really know my stuff". I'm just this schmuck who, not knowing any better, sandblasts a lot of exterior car panels with pretty darn good results.

    Ed
    Yep, I am with Ed on this one. If you have a good guy on the gun you can hard media blast car panels without damage. JR
    The Bridgeport Mill group I started...

    https://groups.yahoo.com/neo/groups/...port_mill/info

  10. #30
    Join Date
    Mar 2008
    Location
    Lombard, IL
    Posts
    124

    Default

    http://www.eastwood.com/paints/elast...gs/quarts.html

    peel it off when your ready and its like you never coated it at all. you can even get it in spray cans.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •