I finally got in the water! After practicing on some scrap I tried putting in a patch on the back rear portion of the cab. I sure was nervous. didn't turnout too bad for the first try. I blew a couple of holes in it. After I ground down the weld beads I tried to improve it by rewelding. Should have left it alone. Now I have to learn how to fill in burn thru. Live and learn. I got all my patch panels from mid-fifty last week. Now I don't know where to start. Any suggestions on where to brace my cab? I got 1 inch sqaure stock 6 foot long on two pieces and two 3 foot long. I was going to put the 6 foot pieces across the width of the cab and the 3 footers tied into them and the cabposts. Do I need diagonals also? I'm replacing front cowls , sills, floor boards,front and back bottom door pillars, firewall , and cab corners. I'm over my head but , I think I've got it in me somewhere.

 

If you need to fill pinholes, use can use a flattened copper pipe. I have a 6" section of 3/4" pipe, smashed one end and hold it in a vise grips. The weld doesn't stick to the pipe and gives a "back" to the hole. Works pretty well for me anyway.
As for bracing, triangulation is the key. Use diagonals if you can. Are the doors on it now? If not, you may want to fit them first, then brace the cab to make sure everything is fitting right.

 

it is good to do for yourself.better than buying pre-built. that copper or brass backer is a good trick.by the time you get finished, you will have become pretty dang good at it.

 

53pickemuptruck Looks like me and you are in the same boat. If it wasn't for holes I wouldn't have any thing to do. I think I'll try the copper pipe thing and see if that helps. Seems like every time I touch it with a Mig I get a hole. Good luck. ..........RUSTY

 

You can also use a thicker metal for a backing, say 3/16". You need to pull it off rather quick though or it can get stuck to the weld. When you are filling the holes just start doing a circle and they will get smaller and smaller as you work your way around and in.

 

The copper backing is definately the way to go. I have several pieces of copper that I use but the easiest thing to do (as the guys have already mentioned) is to grab a drop of 3/4" or 1/2" pipe and hammer it flat.

It seems like I always blow through on the thin stuff and then spend the next several minutes chasing the hole around trying to fill it back in....the copper really helps.

Good luck with it
Bobby

 

I agree with what everyone has said regarding the use of "copper" for backup.

 

Thanks for the input guys! Gonna make some copper spoons and try it out.

 

Copper backing is a big help and don't overlook the usefullness of a decent torch especially where the metal is really thin or badly eaten (holed). I've had better luck with my oxy/acet torch in places than with my mig and by using a small tip you can really turn down the heat required and you get a weld bead that can be worked as it's not so hard as the mig bead. Just be careful of the heat - get in and get out so you don't put too much heat in one spot and warp a panel...guess that's true with the mig too.

I recently got a Dillon/Henrob/Cobra torch for my tanks and while I'm not convinced it's the greatest thing that's ever lived as they'd have you to believe it has given me the confidence to dive in and with the selection of small tips it has improved my gas welding a great deal and there are some places where it seems to work better than my mig....or maybe I'm just a really lousy mig welder? My two cents for what it's worth - keep at it and your skills will improve and when you're done it will be really satisfying that you did it yourself! Everyone here has blown a hole or two in sheet metal and the beauty is that you can fix it yourself!

Keep em running!

OilLeaks