kyteler Posted August 12, 2019 Share Posted August 12, 2019 PPE is your friend. Quote Link to comment Share on other sites More sharing options...
Toddy415 Posted August 13, 2019 Share Posted August 13, 2019 I cleaned mine up with meths as per instructions then wax and grease remover then applied epoxy primer. The epoxy is super easy to chip off / hasn't stuck very well at all so I am thinking I went wrong using the meths. I will try cleaning up using thinners instead next time. Quote Link to comment Share on other sites More sharing options...
Spencer Posted August 13, 2019 Share Posted August 13, 2019 Yeah something went wrong, 2 part epoxy will usually stick pretty good even to a poorly prepped surface. So using the data sheet for something like the protec 408 epoxy primer it says to sandblast your metal or sand it until clean and coat it. Says if you are using new sheet metal to use their acid wash (which is phosphoric acid) to remove the oils, read the data sheet for the acid wash it says to use steel wool to apply and wash with water so you are washing and scouring it, then wax and grease before painting. This is how I learnt from a couple restoration body work guys, backed up by the data sheets of most paint systems. Now epoxy is used as a sealer of old paint so it does stick to other shit and usually well. But you want to test it out and if you go all the way to bare metal I don't see why you would want anything else under it, especially a rust converter primer, they don't have the same adhesion as magic chemically cured 2 part epoxies. http://www.ppglic.com.au/uploads/tds/408 Epotec Epoxy Primer (2).pdf So for all applications its pretty much clean white sanded/scotch brite steel clean with wax and grease and then apply 2 part epoxy. If you have pitting or want to clean it then acid wash with phosphoric, neutralise with water. I would still key the metal up again with scotch brite after the acid wash to remove everything as you can get some residue if the acid wash got dry. Anything else is garbage IMO. Then for safety as said modern epoxy cures with polyamide, old school ones used amine or something toxic (not a chemist). So 2 part epoxy is very similar as other single stage paints as far as safety goes, ie don't breath it and avoid getting it on the skin and eyes. It doesn't have the extra death factor of polyurethane which cure with isocyanate, anyone who has sprayed urethane clear knows how deadly that shit smells. 3 2 Quote Link to comment Share on other sites More sharing options...
dmulally Posted August 14, 2019 Share Posted August 14, 2019 On 13/08/2019 at 12:14, Toddy415 said: I cleaned mine up with meths as per instructions then wax and grease remover then applied epoxy primer. The epoxy is super easy to chip off / hasn't stuck very well at all so I am thinking I went wrong using the meths. I will try cleaning up using thinners instead next time. Sounds like it needed a bit of scuffing first. 1 Quote Link to comment Share on other sites More sharing options...
Lord Gruntfuttock Posted August 14, 2019 Share Posted August 14, 2019 Seems strange. I've thrown Durepox onto greasy, shiny, and rusty old bits when emptying/cleaning gun out, and it has stuck fast every time... Quote Link to comment Share on other sites More sharing options...
Toddy415 Posted August 15, 2019 Share Posted August 15, 2019 31 minutes ago, Lord Gruntfuttock said: Seems strange. I've thrown Durepox onto greasy, shiny, and rusty old bits when emptying/cleaning gun out, and it has stuck fast every time... Thats what I was expecting i might have to do test bits to find out whats wrong a bit annoying but better to find it now i guess. Im guessing its user error not a product issue. Quote Link to comment Share on other sites More sharing options...
Spencer Posted August 15, 2019 Share Posted August 15, 2019 The test is when you sand it back, have had epoxy stick not so well to a bunch of things when you start sanding. When block sanding you will go through your epoxy and/or high build primer and that is the real test, if you have some shit adhesion at the base layer (like some shit single stage rust primer or badly prepped steel) the edges don't feather and things come off in little clumps leaving sharp edges, just making more work by needing filler etc to fix it. Then in the back of your mind for the next 10 years that your paint job is stuck on real shit. You get away with it on internal fix ups where you just poo it on and walk away, it sticks so well to itself that it doesn't go anywhere. 2 Quote Link to comment Share on other sites More sharing options...
Mr Vapour Posted August 15, 2019 Share Posted August 15, 2019 all good interesting stuff. I support reading tech sheets. best way to get things prepped correctly. I'm not far away from engaging a repair cert inspector so will see what processes he wants me to use. he has told me to not even blast till he sees the car. When requested I supply a phosphorous wash tergophos and the coating epiphos (same as keyphos253) I have the epiphos in 20ltrs so if any one wants some let me know. 1 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted August 15, 2019 Share Posted August 15, 2019 Bit off track but: http://www.emdocs.net/hydrofluoric-acid-burn-keeps-burning/ Some rust converters can have HF in them (case study in the link), so be sure to read any datasheets/warnings on the bottle or it could well kill you Quote Link to comment Share on other sites More sharing options...
dabuzz Posted August 16, 2019 Share Posted August 16, 2019 Slightly off track, but in keeping with the 'prep' theme. When you have panels acid dipped, they coat it in some stuff that looks kinda black to stop flash rusting, and can store in for ages. does that have to be fully washed off, or just scuffed up and epoxyed over? Quote Link to comment Share on other sites More sharing options...
Spencer Posted August 16, 2019 Share Posted August 16, 2019 I would scotch brite it with wax and grease at a minimum, see what happens. Or spray a patch then sand it back to test. 2 Quote Link to comment Share on other sites More sharing options...
yetchh Posted August 16, 2019 Share Posted August 16, 2019 23 hours ago, ajg193 said: Bit off track but: http://www.emdocs.net/hydrofluoric-acid-burn-keeps-burning/ Some rust converters can have HF in them (case study in the link), so be sure to read any datasheets/warnings on the bottle or it could well kill you I don't think I've seen any converters with hyroflouric in them, they've all been phosphoric.. That shit is lethal anyway, you need an antidote if you (for some fucked up reason) want to use it.. 1 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted August 16, 2019 Share Posted August 16, 2019 Just now, yetchh said: I don't think I've seen any converters with hyroflouric in them, they've all been phosphoric.. That shit is lethal anyway, you need an antidote if you (for some fucked up reason) want to use it.. I think it is more for cleaning stainless when welding Quote Link to comment Share on other sites More sharing options...
yetchh Posted August 16, 2019 Share Posted August 16, 2019 We used it for cleaning old buildings back in the UK.. Stinky shit, special with no mask. Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted August 18, 2019 Share Posted August 18, 2019 I have heard a mate say they weren't allowed to use some stainless steel cleaner at his work anymore. (He's a TIG welder) perhaps that had that shit in it? I also saw a tech bulletin at a brake shop once saying that certain kinda of brake stuff will convert into that if the car has been burned out. And it will keen burning you in till you get an injection to reverse it. Quote Link to comment Share on other sites More sharing options...
Lord Gruntfuttock Posted August 18, 2019 Share Posted August 18, 2019 Yeah think some o-rings produce it if burned too... Quote Link to comment Share on other sites More sharing options...
SR ROLLA Posted August 22, 2019 Author Share Posted August 22, 2019 Thanks for the input everyone. It's awesome how much knowledge and experience gets shared around on oldschool. Cheers Quote Link to comment Share on other sites More sharing options...
Murph Posted November 13, 2022 Share Posted November 13, 2022 Why add zinc to phosphoric acid? Quote Link to comment Share on other sites More sharing options...
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