Projects Patch panel frustration

So I tried my hand at patching up the fender on my truck, but I am not realy to happy with the results. It's the first time I have done any kind of body work but still It bugs me. Part of the problem is that I dident leave a gap between the two panels. How mutch of a gap should I leave?

 

I like to leave about 1/32" all around, but that's almost impossible to be that exact.
The most important thing is patience. Tack a few spots evenly around the panel, and put down the torch until the panel is room temp. Now tack in between those tacks and repeat the cooling. Continue this until the entire patch is buzzed in.
On low crown areas or areas that start shrinking, bump the weld flat with hammer and dolly to even the panels.

 

I try to leave a gap that is equal to the thickness of the metal I'm using.

 

Which welding process are you using?

 

I have heard thickness of the metal for sheetmetal work...

Are you using mig or gas?

 

Rosati, thanks the pics are great. Now I see how bad I screwed up. Does it matter that I am using a mig welder.

 

The gap that you have on the bottom left side is about what should be all the way around . Still looks good for a first time !

 

Hey Jimmy,

You mentioned the " didn't leave a gap between the two panels " part, and now the problem is ? Too high a surface after welding? High metal can be driven down with a dolly and hammer, and or a shrinking disc.

I don't leave much, if any gap when welding my panels together trying to fuse the two pieces together without much, if any filler rod. I usually hammerweld that which I can get a dolly behind, and as a result, don't spend alot of time grinding down welds. Sometimes that's not an option, but I try and plan my cuts to be able to get behind them, whenever possible. This process work well for gas welding, but not so well for "squirtgun "welds.
A gap of atleast the gage of the metal you're welding, should leave you plenty of room for expansion from the heat. Any welding will cause shrinking, upon cooling which isn't a big problem once the shrinks are stretched back out with a hammer and dolly. Always watch your welding heat!

Swankey Devils C.C.
" Spending A Nation Into Generational Debt Is Not An Act Of Compassion !"

 

Looks like nice work i try and leave the thickness of the wire when welding a patch in . Muddy Waters sang live the life you love and love the life you live.

 

Pimpin paint- Yea the problem is to high a surface, Grinding was a real pain, I am doing the other fender tomorow and will be sure to use your advice. Now I just wish I would have come here before I started.

 

I migged these with .23 wire and 75/25 gas. I now mig most everything with .30 easygrind and only use a "tiger disc" or dewalt flap discs as grinders build too much heat when smoothing the weld.

 

I don't agree with leaving a gap. I've found it works best if there is no gap and make sure you get full weld pentration. When there is a gap the metal will tend to pull together when welding which can then make the area bulge out or bulge inward depending on the stress in the panel. I like to go a step further and bevel both the edges of the patch and base metal and then mig weld in tacks as stated above.

 

That's how's I do it also ....

 

Thats how I do it too.

 

I don't think the issue of a gap is important in your case. You mentioned that this is the first time you've done bodywork???????
What is the actual problem with your work? You didn't mention it!
Making a guess.....you probably warped the panel while welding it? you probably lneed some lessons on how to hammer and dolly out welding warpage.

 

Hey guys I just wanted to thank you for the tips. Just finished the other fender on my truck, used your tips and it came out 100% better than the last one.

 

Cool.

 

That's what makes sharing information worth it. Good results for everyone.