Question for the welders/fixers (1 Viewer)

[EStein]

Question for the experts. Is this fixable? It was the first door I did and I’m kicking myself for using the whole patch and not cutting it down to the minimal size I needed to cut out the rust.(like I did my second door.).
I watched some videos about using a shrinker disc… Or a torch… Would that do anything in this situation? There is quite a ridge along my weld line as you can see in the photo. Doesn’t stand out now but as soon as the paint is on, it’s going to stand out like a sore thumb. I thought about pounding it down but then that would just put a whole bunch of dents in the door I’m afraid.

Any suggestions?

This is how I did my second one which I think is going to turn out a lot better.

 

[Skreddy]

Cut along the peak with a thin cutoff wheel, clamp it flush and reweld it? That’s probably what I’d try.
From what I’ve seen, shrinking with a torch or disc is very hard and may make it a lot worse.

 

[EStein]

Cut along the peak with a thin cutoff wheel, clamp it flush and reweld it? That’s probably what I’d try.
From what I’ve seen, shrinking with a torch or disc is very hard and may make it a lot worse.

Hmm… didn’t think of that. I wonder if it would just do the same thing again? I was thinking that it was probably the heat a couple inches on each side of the weld that warped it up like that?

 

[peesalot]

I am with Skreddy on the fix. If you cant access that weld line from the back its gonna be tough to clamp/hold it. When you weld it as you put the puddle down it adds metal which can spread the gap & build up as you have exp. It will take alot of small tacks, turn heat up and wire speed down until you can tack and it leaves a flat puddle without burning thru, its hard and wind, outside temp, etc will effect it. Test on something until you get that nice flat one spot, repeat alot, if it quites putting down flat puddles stop and adjust, it can be frustrating but once you see that flat puddle you'll get it. I would try putting wood blocks inside door and clamp the outer skin & shim etc until dead flat, then I would tack a few spots ( like 4) across, let cool, grind 1 or 2, check with straight edge, if it worked I would repeat, a few tacks, check, if a spot peaks up, remove clamp at that spot adjust, reclamp with outer skin flat and go again, even if you have to cut out one of the new tacks, it could take me a few nights of tack. grind, check, walk away, repeat. If it burns thru, leave it & fix later, your after a flat skin, holes & spots can be fixed later. After you make the relief cut and clamp it down flat the edges of each side should have a credit card size gap all down the seam. This is a tough one, patience and testing you'll get it. I would get some scrap metal same thickness, roll it up and recreate the problem on my scrap & use the same method to see what happens then you will know the fix will work or not. IMO the tacks in your photos are just putting down to much wire, the heat spread doesnt look to big or to hot just need to tune the set up so it leaves the flat puddle instead of those seeds you got across there.

 

[charliemeyer007]

I think the "tool" is cleco's? They hold sheet metal on airplanes for riveting. You can drill 1/8" holes and hold bracing in place across the butt weld zone in several place, then after you get the patch mostly welded up, use the special plyers pop off the cleco and brace finish your welds and then fix the little holes.

There are some really utube vids for welding sheet metal patches in place. Finding the setting for your welder on scrap of same thickness and type is well worth the effort.

Amazon product ASIN B07B8W7JRQ

 

[EStein]

I am with Skreddy on the fix. If you cant access that weld line from the back its gonna be tough to clamp/hold it. When you weld it as you put the puddle down it adds metal which can spread the gap & build up as you have exp. It will take alot of small tacks, turn heat up and wire speed down until you can tack and it leaves a flat puddle without burning thru, its hard and wind, outside temp, etc will effect it. Test on something until you get that nice flat one spot, repeat alot, if it quites putting down flat puddles stop and adjust, it can be frustrating but once you see that flat puddle you'll get it. I would try putting wood blocks inside door and clamp the outer skin & shim etc until dead flat, then I would tack a few spots ( like 4) across, let cool, grind 1 or 2, check with straight edge, if it worked I would repeat, a few tacks, check, if a spot peaks up, remove clamp at that spot adjust, reclamp with outer skin flat and go again, even if you have to cut out one of the new tacks, it could take me a few nights of tack. grind, check, walk away, repeat. If it burns thru, leave it & fix later, your after a flat skin, holes & spots can be fixed later. After you make the relief cut and clamp it down flat the edges of each side should have a credit card size gap all down the seam. This is a tough one, patience and testing you'll get it. I would get some scrap metal same thickness, roll it up and recreate the problem on my scrap & use the same method to see what happens then you will know the fix will work or not. IMO the tacks in your photos are just putting down to much wire, the heat spread doesnt look to big or to hot just need to tune the set up so it leaves the flat puddle instead of those seeds you got across there.

Oh man. Now I’m getting nervous. I’ve been using .30 wire as well… Should I go smaller wire? I’ll try turning up the heat a bit.

 

[EStein]

I think the "tool" is cleco's? They hold sheet metal on airplanes for riveting. You can drill 1/8" holes and hold bracing in place across the butt weld zone in several place, then after you get the patch mostly welded up, use the special plyers pop off the cleco and brace finish your welds and then fix the little holes.

There are some really utube vids for welding sheet metal patches in place. Finding the setting for your welder on scrap of same thickness and type is well worth the effort.

Amazon product ASIN B07B8W7JRQ

That’s actually an interesting idea to cleco some bracing behind…

 

[Skreddy]

Smaller wire will help a lot. I usually use .023” with my gas shielded mig doing sheet metal. Clecos can work. The thinnest abrasive cutting disc you can find should leave less than 1/8” gap. You can use sheet metal screws in the gap to “clamp” it. Put them every 2” or so and do a tack to one side of all of them. Wait 10-15 minutes then do a tack to the other side of all of them then you can remove screws. Wait 10-15 minutes then do a tack in the middle of each existing tack (not where screw was yet). Now, grind all these tacks flush being very light handed and don’t stay in one spot too long because grinding adds a lot of heat too. Now, go put a tack on one side of every other tack. Lather, rinse, repeat. It is hard to go slow but if I were doing that door and looking for as close to perfection as I could get, it’d take me probably close to 3 hours to weld and grind that weld line. I try to grind as I go because it seems to save heat.

I get really impatient so I try to have another small job I can go to for the cool down period, usually an IPA….

 

[EStein]

Smaller wire will help a lot. I usually use .023” with my gas shielded mig doing sheet metal. Clecos can work. The thinnest abrasive cutting disc you can find should leave less than 1/8” gap. You can use sheet metal screws in the gap to “clamp” it. Put them every 2” or so and do a tack to one side of all of them. Wait 10-15 minutes then do a tack to the other side of all of them then you can remove screws. Wait 10-15 minutes then do a tack in the middle of each existing tack (not where screw was yet). Now, grind all these tacks flush being very light handed and don’t stay in one spot too long because grinding adds a lot of heat too. Now, go put a tack on one side of every other tack. Lather, rinse, repeat. It is hard to go slow but if I were doing that door and looking for as close to perfection as I could get, it’d take me probably close to 3 hours to weld and grind that weld line. I try to grind as I go because it seems to save heat.

I get really impatient so I try to have another small job I can go to for the cool down period, usually an IPA….

OK. I’m going to try this. Thanks for all the input. Patience is definitely a killer for me when I’m doing something like this. I’ll be gone for a few days, but I will report back. Maybe I’ll just end up replacing that whole top piece of sheet metal.

 

[charliemeyer007]

Not a welder, but it looks too hot already to me. Yea you could hold backing in place under the butt weld or brace a stiffener in place across the butt to help keep the two side level and in place.

I have a friend who said he would show me how to weld the patches but he wasn't going to do it all, not even for money.

 

[EStein]

Not a welder, but it looks too hot already to me. Yea you could hold backing in place under the butt weld or brace a stiffener in place across the butt to help keep the two side level and in place.

I have a friend who said he would show me how to weld the patches but he wasn't going to do it all, not even for money.

Haha. Well, I can understand that! Thinking about in a bit and doing a little more research I wouldn’t be surprised if I overheated it during the grinding process. I pretty much did it all at once. And with a 60 grit flap disc. Again… Patience is not my virtue.

 

[Skreddy]

Looking closer at the pics, I would bet a lot or most of that peak formed during grinding due to heat.

Typed this as you posted. Patience is hard. I set a timer a lot of times and force myself to walk away. Otherwise I think “just a couple more tacks won’t hurt….”

 

[EStein]

Looking closer at the pics, I would bet a lot or most of that peak formed during grinding due to heat.

Typed this as you posted. Patience is hard. I set a timer a lot of times and force myself to walk away. Otherwise I think “just a couple more tacks won’t hurt….”

Haha. So true!

 

[aztoyman]

@88repo gave me this link after I damaged my roof.

 

[wimberosa]

I've had similar issues... Its very difficult to get this perfect even going with lowest heat and smaller wire. I use a shrinking disk and am quite fond of it. I would definitely try a shrinking disk on it...pretty foolproof tech....but its not a miracle. I have tried the "cut and reweld" method and am NOT fond of that....it produces yet another void / bulge thats on a completely different plane than the original problem. Best bet for me...is shrink it.

 

[EStein]

I've had similar issues... Its very difficult to get this perfect even going with lowest heat and smaller wire. I use a shrinking disk and am quite fond of it. I would definitely try a shrinking disk on it...pretty foolproof tech....but its not a miracle. I have tried the "cut and reweld" method and am NOT fond of that....it produces yet another void / bulge thats on a completely different plane than the original problem. Best bet for me...is shrink it.

OK I just ordered a shrinking disc. I might mess around with a little bit. If that doesn’t work, then I’m going to cut and re-weld… And if that doesn’t work I’m just going to cut out the whole side of the door and replace it as one big piece of sheet metal. Close to the edges so it won’t warp. Tempted to do that anyway.

Thanks guys

 

[EStein]

@88repo gave me this link after I damaged my roof.

That was a pretty cool watch. Amazing what some people can do. Metalwork has always fascinated me. Now it just pisses me off.

 

[aztoyman]

After all this, WE'LL be the ones asking YOU for metal work advice.

 

[88repo]

OP, if you're able to get a dolly behind it (along entire weld seam), I'd start with hammer and dolly first, starting with light taps and putting the coals to it as needed, hammering on the crowned side. If you're able to flatten it but end up with it oil canning on you in areas, then you can do some spot shrinking with a single or double 0 tip.
Never used a shrinking disk, so can't comment on it.

This may be of help in understanding weld shrinkage:

IDK if he has a vid on it:
https://www.youtube.com/channel/UCtRedgDFHDnLuBO040NdL1g/videos?view=0&sort=da (...wealth of info and technique here)
but in welding seams like you have with mig, he'll start by tacking it (dotting) about every inch or so.
When cool, go back over every weld dot first with hammer and dolly to planish it, concentrating on just the prouds of each weld. Goal here is to neutralize the 360 degree "pull" around each one.
Follow this up by grinding down whatever peaks are left on each dot, leaving them maybe .010 to .015" proud of your base. And grind both sides if possible, unless you want a ghost line in your finished paint work.
After this is done to all your weld dots, go back and add another dot adjacent to and overlapping your first planished and rough ground dot. Follow this with more planishing and grinding...wash, rinse and repeat until your seam is 100%, then go in and do your final finish grind.

Slow and monotonous yes but being able to planish each weld dot individually makes it much easier IMHO to control weld shrinkage than trying to tackle a full length weld seam after the fact.

Hope this helps and g/l.

 

[EStein]

After all this, WE'LL be the ones asking YOU for metal work advice.

I’m always good for what not to do