[Tim_D]

I just finished welding up the first of 2 rear door handles on my '63 wagon. I took my time with the measurement, trimming, and welding, and came up with a warp-free panel. I thought to myself, "this welding thing is easy".

HOWEVER...

After grinding, I had some warpage that approached 3/16" deep in some areas! It took me longer to get the panel semi-straight again than it did to weld it. I thought I was careful to grind in alternate areas, doing small parts at a time, allowing to cool etc - but my process didn't work.

I've got another side to do. PLEASE can someone suggest a process to prevent me from duplicating this mistake?

 

[CRJ]

What type of disc are you using?and at what RPM? Flapper discs work pretty good for minamizing warpage.

 

[boyds67wagon]

Another thing is to keep a damp and a dry rag handy. After using the flapdisck for a bit put the damp rag to it. If it sizzles it's getting too hot. Then wipe off excess water with the dry rag before resuming.

 

[73ss406]

i would use a "vixen" file, its made for body work, very sharp cutting ability and no heat problem.

 

[Tim_D]

What type of disc are you using?and at what RPM? Flapper discs work pretty good for minamizing warpage.

I suspect this was my problem - I used an electric grinder with a thick disc.

I like the suggestion of the cut-off wheel. Perhaps I'll weld a few spots, cool, grind spots with the cut-off wheel, cool, repeat... Kinda sounds like shampoo, rinse, repeat.

 

[evldoer]

I have found that while flapper wheels remove material fast, and do a good job, they create more heat. I sometimes use a cut off wheel like truckin tom, but I also like a 2" grinder disc in 36 grit. The coarser the grit, the less heat it makes,IMO

 

[Chucks71]

Tim,

I also use a thick grinding wheel on edge, 40-60 grit. I don't weld all
the panel like you have done. I tac it in several places, let cool and
knock down the weld to those tacs. Come back and do the next series.
Seems to be a lot less build up (extra material) to take off, less heat
to build.

Chuck

 

[73SSHatchMan]

Would the vixen file take down the actual weld bead? I can see it working on the panel its self but the hard weld bead?

Hummm

i would use a "vixen" file, its made for body work, very sharp cutting ability and no heat problem.

 

[CRJ]

Also would like to mention the welding wire itself can be a factor. I switched to a softer wire. (Im using .032) and it works well. Makes cleaning up the welds a lot easier without creating so much heat. I think the wire is called easy grind?

 

[JRouche]

I have done the door handles and a filler door and some holes in the body. Never had any warping of the surrounding panel.

I form a patch panel, making sure it matches the contour of the surrounding panel just right. Leave just under a 1/16" gap all around to allow for proper penetration and some expansion of the metal so its not pushing a warp in.

I tack in four or five spots for that size patch, look at it, make sure its perfectly aligned and still flush. Then I split the difference in distance between the tacks and tack some more. I do that again and again without cooling, just a short break (a minute or two) in between the tack sessions.

When the tacks are getting close, say a tack or two in distance away from each other I would start cooling with a damp cloth. Then I would do the final tacks, the ones to fill the last gaps and cool every two inches.

Then I would hit it with a 36 grit 3" flap disc. Just touching the top of the tacks, knocking off as much of the bead as possible. A very light touch and control is needed. I have tried the edge of the cutoff disc as seen and described but never have much success. If it slips off the top of the bead it hits the virgin body and places a nice lil track there. And I use 36 grit cause it cuts not buffs. Cutting produces less heat than a worn out disc or too light of a grit.

When its looking close to the surface of the body Ill switch over to the air angle grinder with some 3m 3" discs in 80 grit. Take the remainder of the tacks down to body level and stop. I look for gaps, there will be some small ones. I tack those shut. Knock them down the same as before. Oh, and I dont use any cooling for the grinding work. It doesn't get hot enough. If it does then yer going too fast and leaning too hard or the grit is worn and yer just polishing the metal creating heat. Your friend is fresh grit and low RPM. I throttle the air angle grinder way down and a light touch.

So it sounds slow and tedious but I didnt have to use the hammer on any of the patches. So I save some time and unskilled use of a hammer there. Im not great with a hammer and dolly JR

 

[TechNova]

Panel fitup and welding techniques are very important as JR posted.
You always will have some weld to grind. I start with a 3M 01991 hard grinding wheel on a cut off tool. This is like a cut off disc but it is about 1/4" wide. It allows you to stay on top the weld bead and minimize the gougeing of the metal of you slip off. DO NOT take the weld all the way down with this disc, just get the bulk of the bead off. If you try to take it all the way you will gouge and weaken the metal. Be patient and skip aroung to minimize heat buildup.
After the 01991 grinder go to a flexible type grinding disk.
Flap wheels cut well but put alot of heat into the metal.
I use a 9" diameter flexible disc such as 3M 01928 (36 grit) or 01927 (50 grit). This allows me to grind the last bit of the bead to contour without gouging the metal. Keep the disc moving to avoid heat. I am constantly on and off the trigger to keep the speed and heat down. Lower air pressure would also keep the speed down but you lose torque.
If the metal discolors you are WAY too hot.
You can use a 7" (3M 01922 - 36 Grit or 01921 - 50 grit) or a 5" (3M 01914 - 36 grit or 01913 - 50 grit) flexible discs for areas the 9" won't fit.
The larger disc cuts well at slower speeds so heat is reduced. I use the largest I can fit into the area and then use smaller where necessary.
The small die grinder disc add alot of heat due to their high speeds.
Other methods also work but I have found this method to give the best results for newbies. (I have about 18 newbies every year)

 

[itslow]

Additionally, when welding in a patch avoid creating sharp corners as they will concentrate heat and can increase warping. Instead cut them with a nice rounded edge.