Buick trunk floor panel weld

Hi everyone, I need some advice on patch panel repair for my Buick trunk. There are a number of areas that I will have to cut out the old floor pan and weld in new sheet metal. Unfortunatly I will have to fabricate these panels since a floor pan or patch panels for a buick electra are not available. When welding in the panels would I butt weld them or plug weld them. Secondly, what would be a good gauge of sheet metal to use. This will be my first major welding project and I am hoping to do a good job on this

 

First thing Find out why you are getting water in the trunk. Bad weather stripping holes, etc.
Second thing I would do is pull out the cardboard side panels, remove the taillights, and everything that would get in the way, so you can find out how much rust you will have to repair.
Is your problem area where the trunk pan meets the wheel well? Butt welding always looks cleaner to me, but in an area where it will not be seen I don't think it matters
I would use 20 gauge to repair your rust.
(I am not a welder or claim to be. This is just what I would do)

 

Thanks for the tips, I forgot to get my sheet metal gauge out and measure the gauge of the existing floot pan. The rust is do to years of winter driving in Canada when the car was being used at that time. Would the 20 gauge be a bit on the thin side for replacement metal ? or would 18 gauge be advisable.

 

Try to measure the gauge of what you have. You could go with a thicker gauge, but it may make it harder to keep from blowing through the thinner metal on the car (which is almost inevitable if it is pitted). Sandblast it if at all possible, so you know the extent of where you'll need to be working. I'd recommend a butt weld. A seam weld is easier, but if it ever got water in it again (almost inevitable from road splash), it would be more likely to have rust breed again. It will be a big job either way, so your goal would be to do it once and not have to worry about it. Also, when it is done, if it were my car, I would clean it up real well and paint some POR-15 on it. (Being sure to remove the old paint, and painting the repair area top and bottom). It would seal everything in the repair area. Once metal has been hot (from welding or otherwise) it becomes a little more susceptible to surface corrosion if not treated. As with any good paint, Por-15 is expensive (and very important to apply according to instructions) but its super tough and worth every penny on a car you plan to keep. Yes, this paint is sensitive to UV light, but it will never see any in your case (under the mat and under the car). Good luck!

 

The Por 15 is a good idea, when I redid my truck I used it on the bed and rockers. Regarding the patch panels, I will make card board cut outs of what is needed and then transpose it to the sheetmetal. If I run into some complicated curves I will take it to a local sheet metal guy and have him make those bends for me.

 

Hey,

I'd suggest you use 18 or 19 gage cold rolled sheet. 20-22 gage is a bit thin for a trunk floor, even with beads in it!
Pratice up on your welding until you've no doubts about your ability. Welding test pieces on a bench, and welding panels in position, arn't the same thing. You may need to use plug, lap & butt welds on this project depending on how deep you get into it. Being equally skilled in all will be a big plus for your project.

Good luck,

Swankey Devils C.C.
"Meanwhile, back aboard The Tainted Pork"