I am going to smooth the hood on my 49 chev. Should it be welded solid or can I spot weld it and finish it in epoxy filler. I don't want the filler to crack once it is painted.
This is not an easy one! First make sure you clean that seam as muck as you can (sounds like bgood advice on many things!). Start in the middle and work to each end. Using a mig welder practisr on some similar gauge metal until you can get a good bead. Weld about 1 inch no matter how well it seems to be going don't be tempted to go more, cool that weld with your air blow gun until you can put your bare hand on the weld and the area. Move 3-4 inches in either direction and repeat the process switching the directions each time, fill in the gaps an inch at a time cooling each segment thoroughly. It is a long process but shorter than shrinking out the oil canning, dips or bulges. Even after all that you may still get cracking in the paint.
So if I start in the centre and work both ways to each end say leaving a foot in between welds is that a bad thing or would I be asking for trouble when I come back to fill in those areas?
I would leave no more than 3-4 inches, to big a gap and your inviting some shifting in between, the even stitching makes everything stable but it's the cooling with air that makes it work! be patient it will be worth it and your buds will be impressed with the result especially if they have ever tried it another way themselves.
Gene Winfield said cut out the lips of the 2 halves and make it flat, then weld it. So you can hammer & dolly as you go.
I was wondering about that cutting off the two lips so u could use a hammer and dolly. I suppose a few tack welds just to hold it all together while the lips ar cut couldnt hurt. and then do the 3 to 4 inch gaps. The hood also has 98 louvers
We had a Thread about this not too long ago. Search " Welding Chevy hood " http://www.jalopyjournal.com/forum/showthread.php?t=622738&highlight=welding+chevy+hood
wow thats ballsy DO NOT CUT THE TWO INSIDE LIPS OFF! take terrybles advice you wont go wrong! as a welder/bodyman for too many years his advice is on the money
I'm not going to argue with you... If you think you've got a better mousetrap, more power to you. But I've done a couple, and I've seen some done by others. The ones that looked like a warzone were done by guys who left the lips in....
I remember when I was a kid with a 53 chevy I used fiberglass cloth and bondo to eliminate the split in the hood. Turned out great with no distortion . (I didn't have a welder.)
Yea, I welded one. warped it good! be very carefull. I did it before I found the HAMB so I was "on my own". I can see the benefit of cutting off the lips but have you ever welded two long flat sheets before? if not try on some scrap first.
There is a fair amount of twist or flex in these hoods when you open and close them, at least there is on mine - it has a little bracing nibbled out to move the radiator out, but not that much. I wonder if in the old days they just brazed the thing together with brass rod? That might be one way to cheat and not warp it.
brass will cause any filler work you do to eventually fail. anyone with the ability to cut the lips out and successfully weld the halves together wouldn't be here asking how to do it. that's a big ol' weld. lucky for me, I like the strip down the center and found an aftermarket bull nose for mine so I will never know for sure if I could weld my hood together without warping the hell out of it.
Why NOT cut away the lips? Why keep them? You'll want to continuously butt-weld the halves together anyway.
Did one years ago, kept the braces in, take your time, weld a spot, move to another area, weld, other side, etc.. before you know it, solid weld, 36 grit disk, smooth the emblem holes as well, sink an antenna, good to go
butt weld it solid, a little at a time, keep a wet rag beside you as you work, alot easier to control the shape of the hood, after your done come back and massage the seam smooth.
OK, just to clarify what's going on here......the method you use, depends on your level of skill, and how much filler you think is acceptable. To some, like metalshapes, Highlander, and others, an almost perfect welded seam is what you should strive for. Cut out the flanges, and gas or TIG weld the seam, hammering and dollying the seam as you go. IF, and that is a BIG IF, you are a good metalman, you can hammer and dolly, and do a little filing, and get it perfect. Takes practice and experience to get there. Most production bodymen think this is impossible, but I assure you, there are craftsmen out there that can achieve this! If you are not as proficient, it would probably be better to MIG it, go slowly, skip around with your VERY short wled beads...I woudln NEVER do a whole inch at a time, that's inviting touble on a flat area like a hood! Keep tacking it until you have tacks an inch apart, again, skipping around to avoid too much heat build-up in one area. Then go in and fill in between the tacks, perhaps doing 1/4 in or less, at a time. I never found that using a cold rag or air helped stop warpage...once you get the metal hot, it shrinks, no matter how fast you cool it. Fill the seam completaly, NO GAPS! You will probably still find you've got some warpage. unfortunatley, you really cannot correct it the right way, the flanged seam, and the MIG welds make it impossible. You;ll just have to correct it as best you can 'around' the weld seam. I've done a few like that, even using lead to fill the bad areas, and haven't had any major failures. But even this "easier" way, it isn't easy! Even doing it this way, you'll have quite a bit of filler to use, and on an area like a hood, subject to worse heat and cold cycles than the rest of the car, as well as engine vibration, and hood slamming, you might get cracking eventually.
using a mig welder, this is almost exactly how I did mine. I kept the flange. if I had this to do over again, I would take the hood apart to properly remove the paint from the inside edge of the lip. before welding I had my hood media blasted to remove all the old paint and undercoating, then primed it to prevent rust. the primer on the inside of the lip area contaminated my weld here and there. I spent about a day and a half making lots of small spot welds, immediately rubbing each hot weld with a wire brush to absorb some of the heat and keep the heat from traveling out too far from the weld area. I don't like using compressed air or a wet rag on welds, I think it cools the area too fast and that can lead to warping. ( that is just my opinion.) my spot welds were as small as a pencil eraser up to no larger then my pinky nail to help keep the heat down. I started at one end, made a few spot welds, allowed the welds to cool completely. then another few welds. fully welded, no gaps. grinding the welds can develop just as much heat as welding so take it slow.
same exact way i did one and it came out fine,you HAVE to keep the heat down,it WILL warp .still needed filler but no problems so far
I did mine a few months ago. VERY slowly but it still warped. No panic, it's only metal; so everything will be well in the end.
Shrinkage can NOT be stopped by a wet rag or an air hose. The RIGHT way to do it is to remove the flanges and butt weld it. Control your shrinkage with a hammer and dolly!
Wow lot's of input and I certainly appreciate it all. Now I am going to ask a dumb ass question. I was talking to an old school tin whacker and I mean old. He made some of the same suggestions that have been made here. but then a little smile came across his face and he said prep the tin the way you should and use a high quality auto panel adhesive like they do on the new cars fill it and fair it and there you go. Problem is I don't know if he was jerking my chain or not and he has been known to do that from time to time. I can mig not to bad but I do not have access to a tig. Either way I m now comitted and it is going to be done.
He was being sarcastic. I'm sure a LOT of young guys want to do things the easy way, Not the old fashioned way, or correct way. Too much work/effort/talent required. Hopefully there are more guys on THIS forum that WANT to learn/do things the old fashioned way!
There are panel adhesives that stick so well the metal will tear before the adhesive gives away, it may be another option. I would try throwing that term in the search feature to see what comes up -
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