So Whose Good With Automotive Bodywork?

[CJM]

Since I have owned my pick up there is a crack/dent in the tailgate. Apparently someone backed into something at one point but the bed liner was on it. Thus it dented and cracked the metal but the plastic bed liner just has a nick in it.

So I decided Id finally fix it. I used some bondo metal filler with pretty dang good results-except the spot where the crack is keeps coming back no matter what. Everything is looking good but that spot. The crack runs over the top of the tailgate about 3 inches longer overall and is 1/16" wide at most (if not smaller).

I thought it might have been me using to thick of filler, nope I barely had any on there the last time I tried and it still comes back.

Friend of mine suggested I use some glazing putty, maybe the metal filler was no good. Still no luck, it fills the crack but when its dry it comes back again.

So Im left with 2 choices:

1. Strip it all back down again (thats gonna SUCK!) and have someone weld it-hopefully not burning thru everything. Then of course I know it should be ok-but the chances or burning thru is high and this will only cost more money cause I gotta pay the guy.

2. Fiberglass it, which I think might work. Looking over bondos website I find they have a fiberglass-hair (as they call it) body filler that claims to be stronger than anything else. They claim it can be used to fill holes, repair rust holes as big as an inch, etc.

3. Epoxy the crack using JB weld, then bondo over that. Not sure how well this would work, I suppose the epoxy would hold the crack together but IDk long term or if the bondo will cover over it without reacting.

So what should I do? I lean towards #2 only b/c its gonna be easier and I think will hold up better

[CJM]

Picture, aint the best but its hard to take when its sunny outside. I circled the crack, it runs all the way from the top of the tailgate (the picture) down and onto the back of the tailgate.

[OldGuyonaQuad]

I would paint a scaled down version of Roseanne's @$$ there and the crack might work ;)
I will ask my brother for you.

8,635 posts? really? I'd call you a whore but most all of your posts are of substance.

[edwardsp&b]

I have been around shops all my life.......the proper way to fix that is to weld it up, grind weld smooth, and redo your body work. Also the green finishing putty is to be used after your bondo. It's used to make it extra smooth, and ready for prime. You could probably get away with fiberglass hair and rosin, but I would go look for a product called mars glass, it's simply fiber hair and bondo type mix that is used with a hardner. Fiberglass will last for a while, but it's just as much work as welding it and redoing your work. I wouldn't fiber it, weld it and be done with it.
Bryan

[CJM]

Haha very funny Tom.

Im gonna see if I can get someone to weld it for me. I can weld but I know ill destroy it if I do it myself.

[dheemstra]

I would defineitly mig weld it up first, but if you dont have that available I think "kitty hair" (fiberglass filler) would work fine.

[Pacheco_450r]

Originally posted by CJM
Haha very funny Tom.

Im gonna see if I can get someone to weld it for me. I can weld but I know ill destroy it if I do it myself.

Mig can blow through thin stuff pretty easy too so be careful. Tig would be the best since the heat can be controlled a lot better and ran cooler plus its a lot stronger than mig. Good luck!

[quadrcr161]

Originally posted by Pacheco_450r
Mig can blow through thin stuff pretty easy too so be careful. Tig would be the best since the heat can be controlled a lot better and ran cooler plus its a lot stronger than mig. Good luck!

You can weld it even with fluxcore wire, just turn down the heat and do a spot at the time to keep it from getting too hot. In that spot it shouldn't be any trouble,

[CJM]

Yea thats why I want to stitch ever so slowly. Dont know anyone with a tig, got a few with migs tho.

Thoughts on kitty hair aka bondo with fiberglass?

[KKiowaTJ]

I have been in the auto body world all my life. Only shade tree hacks use "bondo" brand bondo. Its **** and even the fiberglass green thick stuff will last a year.

Tig weld?? Yeah right, Good luck. That builds too much heat at the minimum range. A small buzz box welder or mig is whats needed with .030 wire.

Its just like welding two beer cans togeather. Take your time, Stitch and bounce around to other corners every stitch. Have a bucket of water and a sponge to cool every stitch, If you want it done correct.
Pistol grip grinder to flush it out and get a quality body filler, Best bang for the buck is rage filler and can be had at carquest etc. If your body work has more than 1/8 of an inch of filler, Thats too much and you need to take bare again. Anything more than 1/8 is a bondo buggy and a half assed job.
After it looks good use etch lock primer and a couple coats of reg. grey. You can add sealer but IMO its not worth it for a tailgate. Pick a good paint and take your time dusting it on so it semi matches. Dont put the cover back on for a couple weeks and let the paint materials etc dry so it wont crack as fast.

Good luck either way, IMO id get some HD bed liner and coat the gate with that after the fix. Just mask it off about 1/4 inch past the lip and it will be good to go. To each his own, Good luck

[wilkin250r]

Originally posted by Pacheco_450r
Mig can blow through thin stuff pretty easy too so be careful. Tig would be the best since the heat can be controlled a lot better and ran cooler plus its a lot stronger than mig. Good luck!

No and no.

Mig is best because it's fast, the electrode and filler are one so the welding is almost instant. You weld in bursts about a second long, its really a series of tack welds. You weld a quick spot, then move to a different area, constantly moving your welds around so you're not building up too much heat in one spot.

You would have to be REALLY good with a tig to get an arc started and get the filler rod melted and in place within 1 second, over and over and over. Even if you could manage a constant weld without burning through the sheet metal, the heat buildup would cause massive warpage.

This shows a stitch weld in progress, it's about 1/4 to 1/3 complete.

[89trx250r]

This guy is pretty awesome welder I have watched a bunch of his videos here are a few with super low amp tig welding of razor blades and soda cans.

http://www.youtube.com/watch?v=WSi5eRTIOa4
http://www.youtube.com/watch?v=eX_sepp9T_M

[CJM]

Thanks guys. But after removing all of the bondo I had on there I realized-this cant be welded without a patch panel-I aint getting that froggy. Glassing it will work just fine.

The spot is on the top and inside of the tailgate so its not all that easily seen. Even so the trucks 16 years old, it aint gotta be perfect.

[quad2xtreme]

Originally posted by CJM
Thanks guys. But after removing all of the bondo I had on there I realized-this cant be welded without a patch panel-I aint getting that froggy. Glassing it will work just fine.

The spot is on the top and inside of the tailgate so its not all that easily seen. Even so the trucks 16 years old, it aint gotta be perfect.

Betting the fiberglass will just pop loose. I've put more fiberglass components like scoops and fender flares on cars than I care to remember and even that was difficult to stick. Hope it works for you. Without feeling the give, I can't say 100% but if there is any give at all I'd say it will come loose.

[CJM]

Hope it sticks.

[Pacheco_450r]

Originally posted by wilkin250r
No and no.

Mig is best because it's fast, the electrode and filler are one so the welding is almost instant. You weld in bursts about a second long, its really a series of tack welds. You weld a quick spot, then move to a different area, constantly moving your welds around so you're not building up too much heat in one spot.

You would have to be REALLY good with a tig to get an arc started and get the filler rod melted and in place within 1 second, over and over and over. Even if you could manage a constant weld without burning through the sheet metal, the heat buildup would cause massive warpage.

This shows a stitch weld in progress, it's about 1/4 to 1/3 complete.


Six years industry experience tells me otherwise. Yes small tack welds with mig is fast, but very very weak! You are melting more wire than base metal which is acting more like a glue than penetrating and mixing with base metal. Low amp tig will not warp thin sheet metal anymore than tacking with mig if done correctly and those welds will last forever. you can start a tig arc at as little as 5 amps so arc starting would not be an issue.

[wilkin250r]

Originally posted by Pacheco_450r
Six years industry experience tells me otherwise. Yes small tack welds with mig is fast, but very very weak! You are melting more wire than base metal which is acting more like a glue than penetrating and mixing with base metal. Low amp tig will not warp thin sheet metal anymore than tacking with mig if done correctly and those welds will last forever. you can start a tig arc at as little as 5 amps so arc starting would not be an issue.

I'm not doubting you, and I'm not in the industry so you would probably know better than I. But most autobody techs I know use stitch welds with mig. Maybe because they're painters, not welders.

[CJM]

Got some pics before/during the repair. Sadly I just noticed I was a bit off drilling the one hole in the first pic. However that spot wasnt a large crack and its on the inside-which i wontever see. What I was mainly worried about is the 2nd pic. You can see the divot from someone backing into something and my subsequent hammering it as best as possible and removing the paint.

In another hour or so Im going to add a second layer of glass to reinforce this everything. Then sand and wait for dry then fill, sand and paint. I got some exact match spraypaint and clear coming sometime this week. Was going to do real out of the can paint and HVLP gun with a compressor but it only needs to be blended at best. If I wanted to I suppose I could repaint the tailgate but thats more trouble than its worth.

http://i49.tinypic.com/30di8aa.jpg

http://i50.tinypic.com/2061xj5.jpg

http://i46.tinypic.com/10ht98h.jpg

http://i50.tinypic.com/25i5001.jpg

[Pacheco_450r]

Originally posted by wilkin250r
I'm not doubting you, and I'm not in the industry so you would probably know better than I. But most autobody techs I know use stitch welds with mig. Maybe because they're painters, not welders.

I'm sorry, I didn't mean to sound defensive. But I agree, a lot of those guys go the cheap way out!




CJM, Looking at those pics that's a tough one! your glass work looks good, hopefully your hard work pays off, keep us updated!

[CJM]

Thanks Pacheco.

Right now Im working on filling it with bondo. Almost done, just need to sand a bit more and do some glazing putty.

[Ruby Soho]

for something like that i would go with the fiberglass. if you do it right it works great.

on a hotrod or something like that i would go through the trouble to weld and all that.

as far as all the welding convo- if your any good with a mig you can do it fine. and same goes for tig. you can turn that machine down way cold till you penetrate just the right amount.

you also would have to watch warping even with tacks from the piss welders.

this is something i fiberglassed. was the famous superduty cab corner rot hole, the entire thing was gone

https://sphotos-a.xx.fbcdn.net/hphotos-ash4/385962_10150409106021493_379576161_n.jpg

[CJM]

Nice Ruby.

I been working at it some more. Im thinking I should have glassed it more so I didnt have as much bondo-but its a bit too late now. Its coming along nicely tho.

[Ruby Soho]

im sure you will get it to work out just fine. post some pictures when its all done