Failed Arms for My First Spot Welder Build.

Epic Fail. having seen several DIY welders, I though I'd make my own. I originally made the arms out of a lexan plastic, the thought being that the lexan would stand up to electrical current and not conduct electricity. Unfortunately for me the last night and it had a lower melting point than I originally thought. the other piece that I had used is not picture to hear because it cause A catastrophic meltdown

Comments

[pfred2]

What you want is called Micarta. I made a frying pan handle out of Micarta years ago and it got a little toasty but it has pretty much been holding up. Micarta is the brand name but the same material is sold under the generic name of phenolic sheet. I have a slab here an inch thick. Stuff ain't cheap. But it is pretty much the best thing going for electrical insulation. It is that brown kind of shiny stuff you see like inside motors for the terminals. It is often mistaken for Bakelite. You can make your own homemade Micarta. Folks do it to make custom knife handles, or scales they call them. Just get some fiberglass resin and rags. Then you make a mold and pack it in there. There are guides on the net. I don't know how good it is compared to the real thing, but probably good enough. Using fiberglass might even be better? There is glass sheet too, I have some of that.

Wow the noise level is so high on the term Micarta now on the net. All I'm seeing is the homemade stuff. Phenolic laminated sheet seems to be the better term now.

[Nuonaton]

And expensive! I went with Aluminum with the standoffs made from the same plexi. It melts at around 280f so I bout some 149f thermal switches to install on it. No install yet, but I think it's a sound idea.

[pfred2]

Like I said in my previous comment you could go the homemade route if the name brand material is too rich for your wallet. But I cannot know how well that will perform. Probably pretty decent if my attempts at burning some fiberglass with a cutting torch are any indication though.

[Nuonaton]

the aluminum arms soon to be holding up very well, but I need to install the thermal switch soon because the contacts wear out too quickly as they heat up. another solution might be to use sticker contacts but currently I can't seem to find thicker copper. I originally thought that ground rod would be a good choice but it turns out that most of it is copper wrapped iron.

[MikeR3]

How long is your duty cycle? It's amazing how fast that much current can heat up the wiring.

Maybe a heavier wire - or copper straps wouldn't get as hot.

[Nuonaton]

No duty cycle. It's on, then off. all controlled by a foot pedal and a safety switch on the back. Someday I'll install a thermal switch on the aluminum arms, but for now I just need to be smart in operation. I only use it for one task and rarely for more than about 8 seconds at a time.

[Nuonaton]

No duty cycle. It's on, then off. all controlled by a foot pedal and a safety switch on the back. Someday I'll install a thermal switch on the aluminum arms, but for now I just need to be smart in operation. I only use it for one task and rarely for more than about 8 seconds at a time.