Register now to get rid of these ads!

Technical Painting rusty hood ?'s. Need some direction please

Discussion in 'The Hokey Ass Message Board' started by 56MercMan, Aug 9, 2022.

  1. 56MercMan
    Joined: May 22, 2008
    Posts: 131

    56MercMan
    Member

    Any help/Direction is appreciated. I have searched google, YouTube for videos and this site and could not really find an answer on how I should proceed with a rusty body panel (All info either deals with clean parts or rusty small items like steering/Chassis components):

    If anyone knows of a good thread I should read please feel free to point me in the correct direction. All I found was paint prep, painting ?'s and so on. Nothing really dealing with a rusty panel.

    I replaced my smashed up 1956 Mercury hood with this one:

    20220809_133744.jpg

    20220809_133733.jpg
    Some surface rust and 2 small rust holes in the front lip. Other then that it is much nicer then my old one.



    My plan:
    1) Strip the hood (once I figure out best option)
    2) Primer with epoxy primer
    3) Fix dents and rust holes
    4) Epoxy primer fixed areas
    5) Sand epoxy primer to give the high build something to bite into
    6) Highbuild primer
    7) block sand
    8) Paint with white

    My questions:
    1) To strip the hood should I use paint stripper or do I just hit it with a DA until all shiney? I usually use paint stripper and then prime but never dealt with this amount of surface rust.

    2) Do I need to do anything special because of the surface rust before priming? I have seen vides on water/vinegar washing it??

    3) Final paint... Any ideas if I should use a single stage or something else? Want the paint to look similar to stock so I will be getting the factory color mixed up.

    4) Anyone see any issues or tweaks I should make with my plan?
     
    Last edited: Aug 9, 2022
  2. If you could find a soda blasting company I think they could take the rust off.
    Or a redneck way would be to get an old plastic backyard swimming pool, fill it with a 8:1 ratio of molasses to water and let it soak for a couple of weeks. Molasses bath does wonders with rust...:)
     
  3. Doublepumper
    Joined: Jun 26, 2016
    Posts: 1,546

    Doublepumper
    Member
    from WA-OR, USA

    A soak in citric acid is another option. Cheep and easy.
     
    Greenblade, Crafty and Budget36 like this.
  4. 42merc
    Joined: Dec 19, 2010
    Posts: 896

    42merc
    Member

    Soda blasting will not remove rust.
     
    gimpyshotrods and wfo guy like this.

  5. I media blast with coal slag, also know as black beauty and use less than 90 psi when doing it. Another option is a 7 or 8" 80 grit disc on a variable speed buffer going pretty slow so you don't heat up the metal. A goo dhood is a real find so spend the time to get the rust gone before you start. You can use a da and do it, it will just take more time and sand paper. The rest of your plan is good. Good luck towards good results. :)
     
    56MercMan likes this.
  6. bobj49f2
    Joined: Jun 1, 2008
    Posts: 1,933

    bobj49f2
    Member

    The roof on my '37 Buick looked worse than your hood. I didn't even consider blasting, especially not with black slag, way too aggressive.

    I suggest using a fiber disc to remove the paint.
    61iRauR+McL._SL500_.jpg


    Then followed up with phosphoric acid and remove the surface rust. I used Krud Kutter brand. My roof had a lot of deep rust pits and I got all of the rust out and had clean, shiny metal in the pits.

    KrudCutter_roof.jpg
     
  7. Whatever mechanical stripping method you use, make sure to go slow enough so you're not building up too much heat = warping....
     
  8. I second these stripping wheels, I use them a lot.
     
  9. Well in that case, disregard my statement. I have never used it, I thought it would remove rust. Learn something new every day.
     
  10. Just did a 55 Chevy hood that looked just like yours,but has 4 rows of louvers to work around. I ran a DA with 120 grit over it,to smooth the rust out then I used Posphoric acid sold as concrete cleaner at the hard ware store.Keep it wer for several hours,and most of the rust comes right off.What doesnt turns black so its dead.Rinse the acid off with water,and dry in the sun. Theres a rust killer primer called Rust Destroyer. Most real paint stores sell it. Comes in a white,and green/blue can with a army tank on it.This stuff has tanic acid in it that kills anything you missed.Its 37 bucks for a spray bomb,but it really works.Have used it for 30 years. Give it a day to dry then put what ever primer on top.
     
    Tow Truck Tom likes this.
  11. gene-koning
    Joined: Oct 28, 2016
    Posts: 4,076

    gene-koning
    Member

    Put me in for the 3rd agree for the stripping wheels.
    Be sure to wear a face mask, and expect to get really dirty!
    Pay attention to where the stripped off material flies to, you may want to protect stuff from the path of material being removed, glass and finished paint can be damaged by the flying stuff.
     
    Tow Truck Tom likes this.
  12. evintho
    Joined: May 28, 2007
    Posts: 2,373

    evintho
    Member

    I too am a big fan of the polycarbonate discs. Chucked in a 4" grinder your hood will be stripped in 10 minutes! I usually buy the Blackhawk 5 packs off Amazon for $40 which are enough to do a whole car. For smaller jobs like your hood, HF sells a single for $6 that's more than enough to strip your hood........
    https://www.harborfreight.com/4-1-2-half-inch-nylon-abrasive-wheel-94017.html

    If it turns out you have pitted rust, sandblasting with TSC Black Diamond coal slag in those small spots will clean the pits out. Surprisingly, even this small handheld will do the job........
    https://www.harborfreight.com/21-oz-hopper-gravity-feed-spot-blaster-gun-95793.html

    The rest of your plan sounds spot on. I just did my '54 hood using the same methods and it came out great!
     
  13. N2hotrods
    Joined: Jul 6, 2010
    Posts: 150

    N2hotrods
    Member

    Do any rust repair, welding and metal finishing before your epoxy primer. You can then do your body work on top of the epoxy.
     
    gimpyshotrods likes this.
  14. Budget36
    Joined: Nov 29, 2014
    Posts: 13,233

    Budget36
    Member

    Are you referring to the Tractor Supply stuff they call Black Beauty “. I think that’s what I read.
    I’ve a need to do a roof on an OT car that’s going to have some pitting on/in it.
    Thanks.
     
  15. KenC
    Joined: Sep 14, 2006
    Posts: 1,050

    KenC
    Member

    Just completed a full strip on a 56 PU. Lots of paint, primer, old bodywork and even some rust.

    Those eBay strip disks work really good. I scrubbed all mine with red pads and Osho to remove or convert any remaining rust. Did all rust through repairs/welding/heavy body straightening followed by a couple of heavy epoxy coats.
     
  16. Dustin 257
    Joined: Aug 20, 2021
    Posts: 281

    Dustin 257
    Member
    from Dallas

    Just remember to read the tech sheet on the epoxy. Most epoxys doesn’t like the acid metal preps under them. I would at least wash it really well after the acid if you go that way.

    like others the striping wheels are awesome.
     
  17. evintho
    Joined: May 28, 2007
    Posts: 2,373

    evintho
    Member

    Yep, Tractor Supply Co. It's called Black Diamond blasting media (coal slag). Make sure to get the red bags. That's the fine media. The black bags are coarser stuff that'll tend to clog the nozzle (unless you have a monster compressor and blasting machine).

    https://www.tractorsupply.com/tsc/product/black-diamond-fine-blasting-abrasives?cm_vc=-10005

    It wasn't that long ago this stuff was $6 per bag!
     
    Budget36 likes this.
  18. KenC
    Joined: Sep 14, 2006
    Posts: 1,050

    KenC
    Member

    True, I failed to mention that in my post. One of the reasons I've settled on Kirker epoxy. Easy 50/50 mix and OK over acid.
     
  19. Bob Lowry
    Joined: Jan 19, 2020
    Posts: 1,508

    Bob Lowry

    I was a skeptic when I heard others on this site talk about how great citric acid works. I used it about 6 months ago on 4 sbc crankshafts that were super nasty. Soaked them for 48hrs and got 5x the price I was asking before the citric bath. I failed to take photos of the before and after shots, but this week I soaked a '64 bumper corner in a big plastic
    tub and did do photos. These parts were simply hosed off, NO scrubbing. As mentioned in a previous post, you may want to think about getting one of those cheap kiddy pools and do your hood in a two step process. First the front, then the top. Here's the photos:

    bumper9.jpg

    bumper5.JPG
    bumper10.jpg
    bumper8.JPG
     
    Last edited: Aug 13, 2022
  20. NoelC
    Joined: Mar 21, 2018
    Posts: 668

    NoelC
    Member

    Well that's just simply stated is an amazing transformation. Truly is. If he isn't convinced on the merits of making a hood bath over a solid afternoon and evening of noise and dust, it's probably going to take a 2x4 to knock some sense in there.
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.