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Metal prep |
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rsrguy3
AMC Addicted Joined: Jun/24/2012 Location: Utah Status: Online Points: 660 |
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Posted: Jan/25/2022 at 8:02am |
What do you like to use on raw steel to prep for epoxy primer?
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javguy
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6749 |
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If it's all clean, a final wash with acetone and dry air to remove any oils (usually from the inherent habit of people touching just before applying primer) and dirt. Acetone evaporates quickly and primer can be applied within a few minutes.
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hassyfoto
AMC Addicted Joined: Nov/16/2009 Location: Maryland Status: Offline Points: 3378 |
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There are many ways and products to prep the metal. I like to use as two part system and on occasion a three part system. As already mentioned Acetone can be used and available from local stores. If the metal has any surface imperfections I will use a metal prep, then wipe down with a damp rag ( multiple no lint towels) and finally with a "wax and grease remover". .
Most products that remove oil based contamination ( oil in the skin, shop products, etc) do not necessarily remove water based products, ( soda, food etc). ( Something that was on your hand or placed on the car). . Sometimes with surface imperfections, a metal prep product is used to help eliminate possible surface contamination. These products can be expensive and can require multiple steps for application and removal. . There is plenty of information on the internet about professional products used in a shop. I would do some homework and decide on what best fits your particular situation.
Edited by hassyfoto - Jan/26/2022 at 4:24am |
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Murphy's Law:
Any given mechanical job you decide to solve alone will imminently require a third hand, at its most critical moment |
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mmaher94087
AMC Addicted Joined: Apr/01/2008 Location: Arizona Status: Offline Points: 1676 |
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Don't forget a Silicon remover.
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Mike
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Steve_P
AMC Addicted Charter Member Joined: Jun/28/2007 Status: Offline Points: 3759 |
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all of the auto paint mfgrs sell a product called something like "wax and grease remover". It's not cheap, but a gallon will do many cars. If you want to etch the metal, like done at the factory, POR15 makes an awesome product to do this.
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RogerS.
AMC Apprentice Joined: May/01/2021 Location: SW Florida Status: Offline Points: 122 |
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I highly recommend a product from Sherwin Williams called R7K158. Fast drying and removes wax, oil, grease and silicone. It's impressive what it will put on a rag even after an initial good cleaning with either lacquer thinner or mineral spirits.
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First_Gear
AMC Addicted Joined: Jan/18/2010 Location: Mukilteo WA Status: Offline Points: 644 |
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I wash raw sandblasted parts with dawn dish soap and a stiff brush. Use hot water and dry it quickly with air to prevent rust. I don't like using solvents and a rag because the lint becomes stubbornly affixed to sandblasted metal (ask how I know)
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Regamble1969
AMC Apprentice Joined: Dec/01/2021 Location: Boise Idaho Status: Offline Points: 204 |
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If sanded to metal: If the metal has been sitting for more than a day, sand it with a red scotch brite or 320-600g sand paper. After that, use a wax and grease remover to clean the metal (follow the directions carefully, I've seen more than one paint job ruined by not following the directions carefully). If you don't have any, a decent lacquer thinner will work in a pinch, but go over it twice at least. Wipe it on with one hand while drying it off with a clean, dry towel in the other hand. Don't let it evaporate off, wipe it off while it's still wet. Do small areas like 1/2 a fender or 1/2 a door to make sure you're getting it off while it's still wet then move on. Use a different rag for drying on each section and turn it over as the product dries to keep from running a contaminated rag over the area. Then tack rag and shoot the epoxy. After blasting: use a red scotch brite with lacquer thinner to clean the surface of the blast media. Then I use an after blast metal prep (Eastwood's has a pretty good one that's not horrible price). After blast is like cold galvanizing and will protect the metal from flash rust. Then, same as sanding, grease and wax then tack rag and shoot the epoxy. Remember, epoxy primer should have a 15min induction period. This means that you mix it really good with the catalyst and reducer (if applicable) and leave it in the mixing cup for at least 15min. Do not skip this step. And this induction period is at 70° so if it's colder, give it more time. They usually have about an 8 hour pot life so letting it induce for 30-45min isn't going to hurt. Then stir, pour, tack rag, and shoot.
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