Goat Posted October 9 Share Posted October 9 Hi paint gurus I've done a bit of searching on this thread, and it seems like 2k Epoxy primer is still the go for painting bare metal. Would a product like this be all good to use: https://totalbodyshop.co.nz/products/concept-ep41-epoxy-primer-grey-kit-5l?_pos=6&_sid=3f6b0ee70&_ss=r Would one be able to 2k color over that after sanding it? Or would i need to prime over that with something like this: https://totalbodyshop.co.nz/products/copy-of-concept-hs-2k-primer-high-build-fast-hard-kit-beige?_pos=5&_sid=eb6e493cd&_ss=r What is the difference between 2k epoxy primer and 2k high build primer? And where would i use one over the other? Quote Link to comment Share on other sites More sharing options...
Goat Posted October 9 Share Posted October 9 Also, for the underside of a vehicle, If i want the coloured underseal look. What process would i do? Bare metal 2k Epoxy Seam seal Underseal? Prime again(epoxy? normal 2k primer)? 2k Color? Quote Link to comment Share on other sites More sharing options...
Spencer Posted October 9 Share Posted October 9 OK quickly typed burb of text... The concept stuff would be fine, I would try find some protec epoxy primer specifically epotec 408 (called PPG epotec now as bought by them like 8 years ago) just because a bunch of us have used it and I can vouch for it. The concept stuff is basically the cheapest brand, I have heard mixed results from the base and colour system they have so I would not use it. But its probably 100% fine. There are so many brands of paint and different systems, its never ending. So like a old barry I just use what I know, apart form clear coats I fuck around and try different ones in that department. Epoxy primer on metal, then 2K urethane (base+clear or single stage colour) on top is fine for engine bays, under cars, inner guards, interior floors etc. 2 part high build is urethane primer and sands 100x nicer than Epoxy, you use it to block down panels before applying your exterior top fancy finished coats, I only use it on exterior panels generally unless you were going show car spec on your engine bay. My favorite for engine bays etc is to wet on wet apply epoxy then a industrial spec black gloss 2K single stage urethane (because cheap and tough). You can paint 2 coats of epoxy, then after its set up wet coat the 2K colour straight on top, no in-between waiting or sanding stage you go from bare panel to painted in one go. This only goes to shit if your paint system doesn't work this way or if you do not wait enough time (it will wrinkle up) I can vouch that the protec epoxy and 2k top coats all work fine this way even though its not in the tech sheets. Don't have any advise on under-seal being thrown in the mix, most people just do epoxy and colour under the car if they are going for under car colour. I would just do the industrial 2K black as per above as underseal is kinda gay. 2 1 1 Quote Link to comment Share on other sites More sharing options...
Goat Posted October 9 Share Posted October 9 Do you do anything to the bare metal before the epoxy primer? Strip it back with wire wheels and 3m disks. Prepsol Epoxy Prime? What if there is rust staining? (as in sometimes you cant get all the pitting out with a wire wheel) Do i need to neutralize that first? Quote Link to comment Share on other sites More sharing options...
Spencer Posted October 9 Share Posted October 9 You want clean "white" metal for best adhesion, its a cunt of a job on complex panels like under cars etc so, if you have more money than time get it sand blasted and they will epoxy prime it for you. It will save you like 100 hours of messy work. Or if you have the air power then a ghetto sand blasting setup outside can be awesome. So yeah strip discs, wire wheels, chemical paint stripper, DA sander, detail sander etc are all tools in the toolbox to get paint off and metal clean. Usually they all leave a residue on the panel (i guess apart from sand blasting and sanding) that wont come off with prepsol, wire wheels leave the metal a gray colour and that shit never comes off unless you scrub it (paint don't stick to that wire wheel finish at all), I usually finish complex/annoying panels with the green scotch brite pad (whatever the harshest one is depends on the brand) get a big roll from the paint shop as you use 1 million of the stuff. I use a spray bottle of prepsol/solvent and polish the fuck out of the panel until its white, if its a big flat panel you can polish it up clean and white with the DA sander easy as just dont go crazy and get it overly hot. For rust pits get rid of it with acid wash, buy some phosphoric acid from bunnings "ranex" you can dilute it for soaking or use neat as spot treatments read the box, wash with water then polish it up as above as it leaves the metal gray and dull (bad for adhesion). As some discussed above there are more modern enzyme rust eaters around but old barry spec I get the acid out it works fast if you use the phosporic (you have to keep it wet to work so using a weaker acid like vinegar takes ages and lots off applications). Oh and try not to use the acid around body seams as it goes in there and never comes out (and keeps eating the metal whenever it gets moisture), people also freak out about washing a bare panel with water, if you wipe it down with prepsol after (you need to polish/sand it white anyway) its fine it will only flash rust if you wash it off and then leave it around. 4 Quote Link to comment Share on other sites More sharing options...
Goat Posted October 9 Share Posted October 9 Thanks dude! 1 Quote Link to comment Share on other sites More sharing options...
Bling Posted October 10 Share Posted October 10 I used that epoxy primer brushed on the hardtop, no issues so far, but then it only sees proper moisture once a year on average so can't comment on it's longevity. None of my poor quality 1k top coat has fallen off though. If you were local i'd give you what's left of my small 1L tin, but shipping that is a ballache / not economical. 1 Quote Link to comment Share on other sites More sharing options...
JustHarry Posted October 10 Share Posted October 10 9 hours ago, Goat said: Also, for the underside of a vehicle, If i want the coloured underseal look. What process would i do? Bare metal 2k Epoxy Seam seal Underseal? Prime again(epoxy? normal 2k primer)? 2k Color? Just color over the underseal. You'll need to make sure it's paint overable At work we just a Ra Johnson water based one and once it's cured just key jt and paint jt 2 Quote Link to comment Share on other sites More sharing options...
lowlancer Posted October 10 Share Posted October 10 7 hours ago, Bling said: I used that epoxy primer brushed on the hardtop, no issues so far, but then it only sees proper moisture once a year on average so can't comment on it's longevity. None of my poor quality 1k top coat has fallen off though. If you were local i'd give you what's left of my small 1L tin, but shipping that is a ballache / not economical. I've likewise bought some of that stuff - can you give a brief rundown on your prep and application of it? Brushed is all good Quote Link to comment Share on other sites More sharing options...
NickJ Posted October 10 Share Posted October 10 I used concept paint for the Datsun, this was after chatting with the paint rep about what I was after which was a period finish, not show winning gloss. I'm really happy with it, to me the finish "looks" right for a 70s car. Used 408 and concept epoxy primer, the 408 was way nicer to work with, +1 for that. 4 Quote Link to comment Share on other sites More sharing options...
Bling Posted October 10 Share Posted October 10 1 hour ago, lowlancer said: I've likewise bought some of that stuff - can you give a brief rundown on your prep and application of it? Brushed is all good Go with Spencers prep just above. So with his prep, I just rolled measuring cups from the paint store, nice and easy for getting the ratio right. I wear more PPE than most due to other health issues (makes you appreciate what you have a lot more), so used a 3M full face mask (got it pretty cheap somewhere I forget right now) with organic filters. Bag the filters up when not being used as they work X amount of time then stop working. The stuff is smells potent and I sure knew when it wasn't sealing 100% right. I would prep a few areas at once so that what I mixed up was used up. Quote Link to comment Share on other sites More sharing options...
lowlancer Posted October 11 Share Posted October 11 So just had my first crack with 2k primer. Went with brushing on as don't have a compressor/gun yet, but these will definitely be my next purchase. It seemed to tack off extremely quickly - ie; I couldn't get a single coat down on a small part before it started to go off. Lots of brush marks and went on super unevenly. Any idea what would cause this? Maybe too much hardener? Gonna take some serious sanding to get these parts presentable. Edit: second coat went for a roller approach and less hardener - better, but tacking off quick still. Fumes not as bad as expected, but certainly not pleasant. Quote Link to comment Share on other sites More sharing options...
lowlancer Posted October 12 Share Posted October 12 Does someone wanna be a massive GC and link me up a compressor that will be suitable for small paint jobs? eg, a panel at a time type thing, small parts. Not looking to respray a whole vehicle here. From there I assume I'll need to suss a decent gun, water trap, lines... anything else? Quote Link to comment Share on other sites More sharing options...
mjrstar Posted October 12 Share Posted October 12 In my experience 2.5hp 50 litre belt drive is about the minimum you'd want. 1 1 Quote Link to comment Share on other sites More sharing options...
Bearded Baldy Posted October 12 Share Posted October 12 I have done a closed door respray with a 1.5hp 20l supercheap compressor and a $20 spraygun before. Twice actually. Cannot recommend that approach, but doing a quarter panel or door at a time shouldn't be an issue though. Mechanic not painter so don't listen to me. Had more bugs in that one than runs, did it post xmas do many moons ago. 1 Quote Link to comment Share on other sites More sharing options...
Bling Posted October 12 Share Posted October 12 It primer (anything) goes off too quick the ratio is probably wrong. Are you using measuring cups? Quote Link to comment Share on other sites More sharing options...
lowlancer Posted October 12 Share Posted October 12 2 hours ago, Bling said: It primer (anything) goes off too quick the ratio is probably wrong. Are you using measuring cups? Yip. Man it's a messy business, shit goes everywhere. Quote Link to comment Share on other sites More sharing options...
Bling Posted October 13 Share Posted October 13 How exactly are you mixing it? lol I was doing most of mine in the middle of summer (mid 20's I guess) and would probably get at least 15 minutes before it started to go off properly. So I would say ratio was off or maybe not mixed enough? Even early stages of mine going off it was nice enough to apply. So to not even get one part done sounds way too fast. If I had primer left i'd often do another coat, so my going off time might be off a little, was a while ago now. I'd have a bunch of areas around the car ready to go and just do laps till it was all done. Quote Link to comment Share on other sites More sharing options...
lowlancer Posted October 13 Share Posted October 13 17 hours ago, Bling said: How exactly are you mixing it? lol I was doing most of mine in the middle of summer (mid 20's I guess) and would probably get at least 15 minutes before it started to go off properly. So I would say ratio was off or maybe not mixed enough? Even early stages of mine going off it was nice enough to apply. So to not even get one part done sounds way too fast. If I had primer left i'd often do another coat, so my going off time might be off a little, was a while ago now. I'd have a bunch of areas around the car ready to go and just do laps till it was all done. I was only mixing up small batches - 50-80ml worth. The primer itself in the can had gone super thick and gluggy, I mixed it for what felt like an eternity to free it up a bit but suspect I needed a proper tool for this rather than a clean piece of wood. Def no chance of a second coat with a single batch, so assuming I got the ratio right, it must be the fact the base primer was so thick in the can. How does everyone manage getting the paint into the mixing cups? eg, not making a mess and being more precise than just pouring? Noob as questions, sorry 1 Quote Link to comment Share on other sites More sharing options...
Spencer Posted October 13 Share Posted October 13 The normal behavior for expoy primer is about 20-30min pot life at like 22 degrees (sets faster when its warmer), so you have that long of it being spreadable from the pot. It will start setting up very fast on the panel so you cannot play around with it just get it on, that is why brushing is shit house but it works. I have done it on rust panels when I had some reason why I couldn't get the gun out, it will have brush strokes in the finish and need to be sanded back for sure. If you really need to mix the 4L tin up you can get a little paddle that goes on a drill but like 10min of elbow grease should do it. For a air compressor the max you can run on a 10A socket is about 3hp, then in that class of 3hp some are more efficient and have better designs than others but most 3hp compressors will be fine. If you have a 15A plug then you can get 3.5-4hp ones but the price goes up. More air the better, look at one of those china guns posted above I use mine ona 3hp and its mint with the paint and the air turned down. 1 Quote Link to comment Share on other sites More sharing options...
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