[jime46]

I'm restoring a '53 Jaguar and am doing a repair on the hood (they call it a bonnet, but I'm and American so I call it a hood). The lower front opening for the grill is in really bad shape so I'm building a replacement panel for that area. I'm using .060 5052 aluminum and I'm having a terrible time with the welding. I'm not a professional welder, but I've done quite a bit over the years and this one is driving me crazy.

I scoured the pieces with ScotchBrite, then cleaned with acetone, but when I started the weld it looks just horrible. The arc is scattering all over the work, and the pieces blow up black. I continued, and I either blew through the part, or the weld puddles into a big blob. But I continued laying down this mess, then all of a sudden everything calmed down and I ran a perfect bead (at least perfect for me) the rest of the way. I then ground off the nasty first half of the weld and ran a new bead over it. That one went down OK also.

My concern is that I can get away with this type of problem making the repair piece, but when it's time to weld it onto the hood I can't have that happen. That hood costs about $5,000 to replace (if I can even find one) so I need to do it right the first time.

I'm sure I have some sort of contamination, but what?

My specifications are:
Miller Diversion 165
60 Amp
Argon-20CFM
3/32 2% lanthanated
Gas lens
Used both 1/16 and 3/32 filler rod. Same problem with both, but was using the 3/32 when it straightened out.

[MinnesotaDave]

When you did your practice runs on test pieces in the same orientation, did you have the same problem?

[cj737]

I would suggest the following:
Turn your AC balance down to 60% if your machine allows.
Clean the inside of that hood extremely well. Then gently run some heat over it, then wipe again with Acetone.
I think you need higher starting amps than 60, but will need to taper off pretty quickly.
I'd use 3/32" 5356 filler without a doubt.
I'd also "bump weld" that repair to help avoid distortion and blow-through.
Find some nearby spot to clamp your ground directly to the hood, don't clamp to steel. (The age and possible corrosion of where you're clamping can interfere with your HF arc stabilizing).
15-20CFH of argon with a gas lens and a #7 or #8 cup.

These are my recommendations for eliminating possible variables.

[jime46]

Weldmonger,

Thanks for the suggestions. The Diversion welder does not have the capability to adjust AC balance so I'm stuck with it's natural settings although I've never had any problems with that, so I'll have to make do.

I do think you might have something with the ground issue. On the repair piece I made I had it on my steel work bench and the ground was attached to the bench, but I was pretty sure I had a good ground as I had one of the aluminum components clamped to the table. When I do the actual welding of the repair piece to the hood I will have to attach the clamp to the hood, but I'll be sure to clean the clamp area so I'm sure I have a good ground. But if the ground was an issue I'm not sure why it would have cured itself half way through the weld. I also will take your advise to warm up the hood and clean it then. I just wish I had a better idea of why I had such a problem starting the weld. It was the kind of thing I'd expect to see if I had some really dirty aluminum, but this piece was made out of new 5052 sheet, and cleaned as well as I know how.

I did have one more thought that I'd like to get an opinion on. When I sharpened my electrode I used my belt sander to rough it to the proper shape, then used my diamond grinder wheel for the final sharpening. I have an electrode sharpening grinder, but didn't have it out at the time, so just used my tool grinders. Do you think it might be possible I contaminated the electrode using the diamond wheel? If so, could it explain the problem I had? I use that grinder to sharpen my carbide lathe tools, so might have had carbide residue on it.

I just talked to a professional restorer who is coincidentally working on an identical project and he told me he had some problems getting cracks on the hood as he was welding in repair pieces, so he went to 4943 filler rod and apparently helped. He is sending me some of that rod to use. Wonder if anyone has an opinion on the 4943 rods?

Jim

[MinnesotaDave]

4943 is an excellent rod.

https://www.google.com/url?sa=t&source= ... eZu220kSF0

[Warrenh]

I recently had a bottle of bad gas the turned everything black and bubbly. I weld a lot of aluminum and I would think of a gas issue first. Try more gas (even 30 or 40) and then a different bottle if available.

Sent from my SCH-I545 using Tapatalk

[cj737]

Regarding the ground potential, with the weld cleaning up... it’s possible (not saying likely) that as you welded, the ground clamp got hotter and thereby made better contact. Remember, you’re welding DCEN with TIG.

As for the initial part of the weld being sooty, the hotter the piece becomes (heat soaked as you go)the easier it will weld and lower amps needed. So it’s more likely the oxide layer was not being fully melted initially, but ultimately enough heat saturated the part so your welds improved.

I don’t think your tungsten grinding is an issue, personally. 4943 is a great rod, much better than 4043. But I find 5356 is better for this type of application (thin, flexible panels) than 4943 in my experience.

[Bill Beauregard]

I had a Diversion 180. I would not attempt a repair on a very expensive hood with it. You work under a serious handicap with it. Could an expert salvage your project with a Diversion? Maybe.

[OzFlo]

Ahh I see your problem.. you are trying to weld an Aluminum hood instead of an Aluminium bonnet..

Sorry.. just messing with you.

Jags from that era have gorgeous lines. Which model is it?

[Bill Beauregard]

As a teenager, I started working very young, lived with my parents, had gobs of energy, money in the bank, and desperately wanted a Jag. I missed a 1952 XK120 basket case with sandblasted body, and frame, rebuilt engine, and transmission, new leather upholstery. I agreed to pay asking price, but a middle aged man in a Cadillac Eldorado doubled the price, (he wanted it more than me). I eventually bought a 1968 E Type 4.2 roadster with both fiberglass, and canvas tops. I've always considered the E Type roadster to be the most beautiful car ever built.

[MinnesotaDave]

Regarding the ground potential, with the weld cleaning up... it’s possible (not saying likely) that as you welded, the ground clamp got hotter and thereby made better contact. Remember, you’re welding DCEN with TIG.

As for the initial part of the weld being sooty, the hotter the piece becomes (heat soaked as you go)the easier it will weld and lower amps needed. So it’s more likely the oxide layer was not being fully melted initially, but ultimately enough heat saturated the part so your welds improved.

I don’t think your tungsten grinding is an issue, personally. 4943 is a great rod, much better than 4043. But I find 5356 is better for this type of application (thin, flexible panels) than 4943 in my experience.

I thought we were talking about aluminum welding, therefore AC, not DCEN.

[cj737]

Regarding the ground potential, with the weld cleaning up... it’s possible (not saying likely) that as you welded, the ground clamp got hotter and thereby made better contact. Remember, you’re welding DCEN with TIG.

I thought we were talking about aluminum welding, therefore AC, not DCEN.

Right Nevermind that bit-

[MinnesotaDave]

Regarding the ground potential, with the weld cleaning up... it’s possible (not saying likely) that as you welded, the ground clamp got hotter and thereby made better contact. Remember, you’re welding DCEN with TIG.

I thought we were talking about aluminum welding, therefore AC, not DCEN.

Right Nevermind that bit-

Happens to all of us

[tungstendipper]

I've always considered the E Type roadster to be the most beautiful car ever built.

Couldn't agree more! I lusted over these cars when they were introduced.

[jime46]

Thought I'd post an update after all the helpful replies I got to my original question. First to Ozflo, I'm working on a FHC. I've already built a '53 XK120 roadster and got bored after I finished it so decided to improve on all I learned building that one and do a coupe.

I'm waiting for the 4943 rods to get here, so thought I'd try testing some of what has been talked about. I cut up a couple of pieces of the same material I used for the repair piece, cleaned them as before with the Scotchbrite, then cleaned with the acetone. I sharpened the electrode with my sharpening tool and clamped the ground directly to the piece to weld. Weld started up perfectly clean and ran beautifully. Gave me a little more confidence, but am worrying about the comment Bill made about my Diversion 165. I've always known that this machine does not have the capability of more professional units, but so far has done a good job for me on both steel and aluminum welding. Anyway, I know this might start a street fight, but would like to get some recommendations if I decide to upgrade. My only concern is that if I'm used to a machine that all I have to set is the amperage, and getting one that has the capabilities to control all the parameters may just make things worse as I'd be starting all over again.

Jim

[cj737]

It is my opinion that probably the best value TIG box is the Synchrowave from miller if you want a dedicated shop machine and don’t care about portability. Adjustable, capable, and a workhorse of a box. If you want higher end features, a Dynasty has no equal. But they are almost 50% more for comparable amp range.

[metalman21]

Thought I'd post an update after all the helpful replies I got to my original question. First to Ozflo, I'm working on a FHC. I've already built a '53 XK120 roadster and got bored after I finished it so decided to improve on all I learned building that one and do a coupe.

I'm waiting for the 4943 rods to get here, so thought I'd try testing some of what has been talked about. I cut up a couple of pieces of the same material I used for the repair piece, cleaned them as before with the Scotchbrite, then cleaned with the acetone. I sharpened the electrode with my sharpening tool and clamped the ground directly to the piece to weld. Weld started up perfectly clean and ran beautifully. Gave me a little more confidence, but am worrying about the comment Bill made about my Diversion 165. I've always known that this machine does not have the capability of more professional units, but so far has done a good job for me on both steel and aluminum welding. Anyway, I know this might start a street fight, but would like to get some recommendations if I decide to upgrade. My only concern is that if I'm used to a machine that all I have to set is the amperage, and getting one that has the capabilities to control all the parameters may just make things worse as I'd be starting all over again.

Jim

Jim
For what it's worth I have welded tons of aluminum for decades with a plain basic transformer machine. No square wave, balance or frequency control. Included in that was work exactly as you described on aluminum auto panels, motorcycle tanks, etc. Plenty of thin gauge sheet, .032", .040", .050" .063", .070", and on up.
I don't know what caused that problem you had but if you had good results on the bench with the stock your working with I don't see why you wouldn't have good results on the car. Something was causing the problem, you just need to identify what.
The 4943 rod is great and I stock it but I did lots of this type of work before it existed. I used 4043 almost exclusively with no issues. Nothing wrong with 5356 except that it likes to short crack when tacking up a joint and I don't think it's necessary for 3003 or 5052 body panels.
On the attached photo I used sheared strips of the same metal (.050" 5052) I used to make the tank to weld the four separate pieces for a perfect color match. The tank may or may not get finished. I use it as a sample.

[OzFlo]

Thought I'd post an update after all the helpful replies I got to my original question. First to Ozflo, I'm working on a FHC. I've already built a '53 XK120 roadster and got bored after I finished it so decided to improve on all I learned building that one and do a coupe.

Very nice! But we need pictures my dear man.. pictures I say!! Jolly good!