A happy customer

About a year and a half ago I had a guy ask if I could weld repair his favorite wheelchair. I told him to bring it by and I'd look at it. It was some kind of mystery metal that was magnetic. I ended up tig welding it with stainless because I've found SS would often make a better repair than 70S2 when the iron alloy is unknown but not likely to be tool steel. My policy on these types of repairs is to guarantee my weld but not the edge of the HAZ and beyond. So, if the weld breaks, or if the bead breaks out of the part, I fix it for free. Forever. But if it breaks beyond the weld then it's tough beans. It's hard to tell where the HAZ ends sometimes so I figure about .060" beyond the bead is where the guarantee ends. Anyway, all this was explained to the wheelchair owner and he said sure, weld it up. Then, I get a call this morning from the guy. He asks if I remember the job and I say yeah. He says it's still holding and thanks for the good job done. Boy, did that make my day! Eric R Snow, E T Precision Machine

Reply to
Eric R Snow
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Nice work!

Eide

Reply to
Eide

Likely it was 4130. A lot of wheelchairs are made of it.

Wheelchair engineering follows bike frame engineering, just a little heavier.

Be careful using SS as a filler on chrome moly or in any location that will endure a lot of flex. SS is very strong and is excellent for getting a clean weld on dubious metal, but SS also has less ability to withstand repeated flexing.

It tends to stress fracture and then tear out.

So when welding SS you have to make sure the welds will be better triangulated and braced than with steel.

It is for this reason that a SS bike frame would be a huge mistake.

I prefer the Aerospace alloys that are nickle based as filler metals for unknown base metals. They tend not to stress fracture as quickly as SS and are even better at dealing with dirty or oxidized base metal.

Hastelooy W and Inconel 625 are my favorites.

Reply to
Ernie Leimkuhler

Every now and again I'll run into a customer around town that makes it a point to thank me for the job I did for them. I had one guy wave me down in a parking lot to thank me for the custom winch mount I designed and fabricated. Reminds me why I work for my self. Warm & fuzzy feeling for sure. The even better part is the clientele you pick up because your guy gave a referral. That's why I give customers a few business cards each.

Keep it fun

Reply to
John L. Weatherly

Thanks for the advice Ernie. Obviously the weld is holding up so far, but since it's guaranteed forever I'll start looking for a good deal on the above filler rods for tig. Eric

Reply to
Eric R Snow

Having had the good fortune to run into a fair bit of Inconel 625 and HX at Boeing Surplus Several years ago, I'm in an excellent position to heartily second Ernie's advice. I've not had the pleasure of trying the Hasteloy W but I would expect it to be as good. It couldn't be better since how do you beat zero failures?

Ted

Reply to
Ted Edwards

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