DreamZproject Posted March 13, 2014 Posted March 13, 2014 Hey guys, I'm about to start my first go of welding on the car its self, and I just want your opionion on what is best to lay down after the weld. Any sort of special primer? and if there are internal welds that can't be gotten at easily, what should i use there? Thanks guys. Quote
Retro Z Posted March 13, 2014 Posted March 13, 2014 You can use zinc rich weld-through primer or something like KBS rustseal or rustbullet (as i did) then primer filler. For the insides you can use cavity wax spray or fish oil that you spray with a long flexible 360 degree hose nozzle through a small hole that you've drilled. Then plug up the hole with a grommet. Or if you wire brush and clean the weld shortly after welding you can just etch prime over the repairs, but it won't be as good as the above method . Quote
DreamZproject Posted March 13, 2014 Author Posted March 13, 2014 Hmmm ok sounds good. I thought you still had to spray over weld through primer, but i guess that makes more sense. I have read a little bit and heard some good and and things about weld through primer, so i think I'll keep digging, anyone else got an opinion on the matter? I'll defiantely invest in some cavity wax (why the hell would anyone go fish oil?!?!) Quote
DreamZproject Posted March 13, 2014 Author Posted March 13, 2014 OH, am i right in saying that weld through primer is mainly for lap welds? I think I'm going to avoid lap weld where possible... Quote
Retro Z Posted March 13, 2014 Posted March 13, 2014 Hmmm ok sounds good. I thought you still had to spray over weld through primer, You do.. As i said spray primer filler over weld-through primer, kbs rustseal. By the time you are finished you will have several layers of paint over the repaired surface so its just the case of keeping the welded area clean, dry and sealed with what i previously mentioned. Some people also use regular acrylic spray paint and then rub it off with thinners during bodywork. Also plenty of people still use fish oil as a rust preventative hence why they still sell the stuff. Its thinner than cavity wax and seeps into seams abit better. Quote
DreamZproject Posted March 13, 2014 Author Posted March 13, 2014 Ah, ok i get it now. No i just mean the smell of fish oil is such a negative! no point having a car that will never rust if it stinks like a rotting fish Quote
Retro Z Posted March 13, 2014 Posted March 13, 2014 Yeah thats true. I wouldn't want to drive a fish oiled car on a 40+ degree day thats for sure! Apparently the smell fades after awhile but i wouldn't bother with so many other alternatives out there. Quote
nat0_240_chevZ Posted March 13, 2014 Posted March 13, 2014 internal cavities, better option, but more $$$, is lanolin oil. look it up for a bulk 4l is about 200$ from memory!!, still very thin too!!! but yes, phosphate or chromate based etch primers, are your best friends, accompanied by epoxy primers. nat0 Quote
DreamZproject Posted March 14, 2014 Author Posted March 14, 2014 Great thanks guys, that'll get me started. Quote
DreamZproject Posted March 14, 2014 Author Posted March 14, 2014 Oh and one more thing, is the primer that replacement panels comes with a weld through primer, or do i have to strip it off and re spray it? Quote
Scoota G Posted March 14, 2014 Posted March 14, 2014 Oh and one more thing, is the primer that replacement panels comes with a weld through primer, or do i have to strip it off and re spray it? It is not. It is best to remove it. It may have been applied in an unsatisfactory manner. Beep. Humanoid out! Quote
DreamZproject Posted March 14, 2014 Author Posted March 14, 2014 lol, thanks resident humanoid... I'm assuming that it wouldn't take much to strip them, is one of those "scotchbrite wheel" thingo's the best thing for it (the blue worm looking disk that's semi soft?). Quote
Retro Z Posted March 14, 2014 Posted March 14, 2014 That will work but will take forever..and those scotch wheels are very expensive. I used paint stripper. Scrape off. Then pressure wash it, then give it a nice sand all over. Quote
DreamZproject Posted March 15, 2014 Author Posted March 15, 2014 Ok, i thought my questions were done... never... What width should the metal sheet that i use to replace rusted sections? Dad went ahead and bought 1.2mm but i have a feeling that may be a little too thick and could cause problems. Any thoughts? Also, what do you guys use to prep the metal (ready for etch primer) when it has the grease on it from the factory (sheet metal) just degreaser? Quote
Scoota G Posted March 15, 2014 Posted March 15, 2014 Ok, i thought my questions were done... never... What width should the metal sheet that i use to replace rusted sections? Dad went ahead and bought 1.2mm but i have a feeling that may be a little too thick and could cause problems. Any thoughts? Also, what do you guys use to prep the metal (ready for etch primer) when it has the grease on it from the factory (sheet metal) just degreaser? Yep as said go with the .9 Just degrease with the supercheap stuff and before paint you'll need to key the area. I use a flap disc on the grinder as 9 times out of 10 you'll use filler over the area and a rough surface gives better grip. Quote
DreamZproject Posted March 16, 2014 Author Posted March 16, 2014 Yeah i thought that might be the case... Typical dad, tries to help but ends up buying 2.1m x 1m of the wrong metal :/ It's a bit of a struggle atm, he is constantly wanting to jump in and start doing things and I have to shut it down and say plain out no, because I really don't think we have all the information yet and i think it should be approached in a different way. I'm going to be potentially spending 10k on a paintjob, I don't want to find out that we made a rookie mistake by missing out something small and stupid. Eh, anyway rant over. Thanks for the info guys, I'm sure I'll have a few more as i go. Quote
DreamZproject Posted March 20, 2014 Author Posted March 20, 2014 Hey guys, I've had a bit of a search around and can't find .9 I'm wondering if it's because I'm after the wrong metal, some guy told me that cold rolled is the way to go, but i can only find it in .8 or 1.0 (I know they would do, just wanna check cold rolled is the right stuff). Quote
scott Posted March 20, 2014 Posted March 20, 2014 ask for zincanneal, it doesnt stretch and form that nice but for most areas you cant go wrong. If your shaping metal you want black steel but it has no protective coating so it will rust unless treated. Quote
DreamZproject Posted March 20, 2014 Author Posted March 20, 2014 Hmmm, i thought there would be more to this metal selection than i thought. (That makes no sense!) Ok, well ill take that under consideration and see what other people think as well. Quote
Brabham Posted March 20, 2014 Posted March 20, 2014 Use same thickness as original metal - should be about 0.8-0.9mm. If workabilty is what you want, then I believe you need cold-rolled deep draw ca2 - it's bare metal so you will need to treat it. 0.8 is fine. Zinc anneal is ok so long as not too much forming required. For removing oil you need wax and grease remover aka prepsol. Cheers Quote
Retro Z Posted March 21, 2014 Posted March 21, 2014 Or just do what i did and go to a scrap metal place and ask for the metal off a car roof or doors. My car has mazda 3, volvo and skyline metal in it Quote
Scoota G Posted March 21, 2014 Posted March 21, 2014 Or just do what i did and go to a scrap metal place and ask for the metal off a car roof or doors. My car has mazda 3, volvo and skyline metal in it I use donor metal all the time, no point in creating complex shapes if you can find them elsewhere. Fuel tanks are great for around door areas. Quote
DreamZproject Posted March 21, 2014 Author Posted March 21, 2014 That is a very good point! Ok i have the next stage of information i need. Thanks again everyone! till next my knowledge fails me! Quote
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