Show a picture of your welds. Might be just a case of proper machine set up. Cantamination usually results in bubbling, spattering and wierd growths while the weld is cooling. Of course, this is only from my own personal experience.

Wire wheel seams, scrape out what sealant you can with a carpet knife then heat up the seam with a hand held torch and wire brush whatever burnt crap escapes. Once the sealant you can't see has burned, when the mig wire hits it doesn't booger much if any at all.

https://www.miataturbo.net/attachmen...ine=1439215814
Left most weld was the first which I didn't "burn" with the torch, heated the rest up and wire brushed the ensuing soot and got much better results

Oh, yeah. You're good to go.

This is a scrap piece of the car, I'm still new so any advice is appreciated.

I see growths, I imagine I need to get it cleaner? How would I clean between the seams?




Update: Sounds like burn the area with a torch is the solution to cleaning between the pinched seams?

It's not a full blow solution as it doesn't get it all. But I have found it helps greatly.

Also those welds look cold (keep in mind I am self taught and no expert)

^^^^ yes, contaminated and cold. Those worms and mountains are from grinder dust and the adhesive. Blow it all out with air, then weld. And turn it up! You can stitch with lots of heat.

^ not entirely true. My little Lincoln 125 amp on the lowest setting can still burn through the thin stuff. That's probably down to my impatience though and trying to run a longer bead than I should without cooling down.

That's why I used the word stitch. One Bead, wait for orange to cool, then another. Repeat as necessary. It starts to go pretty fast. Not ideal for structural steel building, but fine for a seam on a car. Wire size can have a pretty big effect too, but . 030 sounds fine.

Edit: maybe stitch wasn't the best wording for what I was meaning.

Changed to different size and type of wire. That seems to have made a huge difference, the welds self clean much better and the pools are hotter and easier to control.

My little 110 doesn't seem to have enough voltage to weld with that other stuff.

What are you finding works better? I just bought some 035 wire from NAPA today prepping for some seam welding this off season. I forget the brand name, really didn't think it would matter all that much.

.25 Hobart solid core mig has a copper coating, with argon co2 75/25. Lincoln electric 140 hd, set to d on power, 2 on feed. May not be the best, but seems to be working.

I usually stick to a welding supply shop, but depends on what your Napa has, maybe some nice stuff. I'm using Hobart .023 wire, same as above, otherwise. Copper coated wire and using c25 gas. Cleaning the item being welded is key.

Stumbled on this thread while looking at other people's seam welding. Hope to have pics of my subframe rails and seam welding in the next coming weeks, Chassis is stripped but still removing seam sealer, one panel at a time.

So far, all I've done is subframes and control arms, and other various parts. I had them sand blasted and that saved me prep time. On the Chassis parts I have done, I've used paint stripper (muratic acid) and scotch-lock buffing pads to clean the areas. So far, so good!

Settings seem odd to me. Just saying. Seems hot for any sheet metal on a miata and not enough wire speed.

And you can definitely weld .03 and .035 wire with your machine...

how the hell do you get it to weld sheet on D.

On my 125 amp flux core Lincoln its A and a gnats cock above 1 wire feed. Must be the 035 wire.

Because Flux core burns quite a bit hotter. And...you weld like a pussy. I weld hot as hell, I just move fast.

Not a pro over here. I fully realize I may be doing it all wrong. I would love suggestions on how to do it better.

Less heat was fat beads with less penetration.

I have a bit of vintage Mazda miata sheet I've cut off to run beads on. I will run and take a photo of any combo setting on this wire and gas.

Is it plausible to do this type of work with just the flux core or is running gas a necessity?

I would think the Flux core is the best option. I think you can get wire specifically designed for dirty work.
In fact I would try Flux core and gas if I did any more seam welding

I think a good quality Flux core wire and proper settings you'd be fine. My personal preference is always gas, but if you don't mind the bit of mess, flux core would work.