JB weld.......

I have a small project - repairing a part on a sewing machine. The machine was manufactured in 1890 so there is no option to purchase a replacement part.

The part that broke/is missing was probably cast iron. I have similar machine, with a similar part, to look at to visualize what is needed.

Is it possible to 'shape' or 'carve' JB weld or does it set up/get hard fairly quickly?

Shari

It's kind of runny till it sets up. I have put it in the freezer before so it would hold shape... And also warmed it up to get it to flow better as well.

Have had mixed success with MIG or TIG welding cast materials.

JB Weld is just ordinary 2-part epoxy with metal powder added. Until it sets, it's runny just like any common epoxy. Once set, it's harder than normal epoxy and can be cut or filed (a Dremel tool with carbide cutter works well).

If the part on the other machine is interchangeable, you might be able to cast a mold from it using epoxy (use release agent), then cast a new part of JB Weld in the mold you made.

If the part will be under stress, JB weld may not hold up. If you have a similar part, take it to a shop that does castings (foundry) and have one made.

Ehouse

There is a clay like version of jb weld that we use at work its tuff as nails. I believe it is incredibly strong if you let it set for 24 hours. here is a link to it. we use it to reinforce hydraulic lines in emergencies and it works every time without breaking.

http://www.kmart.com/shc/s/p_10151_...01&srccode=cii_17588969&cpncode=30-78659829-2

pete

Ah yes. JB Weld. Works for so many things. I've even repaired some broken eyeglasses. On a trip and glasses broke. Not so easy fix but worked.

There is also a big difference in some of it. A neighbor bought a car and found out it had a crack and coolant was running all over. He was trying to repair with JB but it would not stick. He'd never heard of the JB Water Weld. So I went home and got some. Quick and easy fix but that stuff can really stink up your hands. lol

Shari there are two versions of JB weld, original and JB Qwik. The qwick version sets up in about 5 minutes, the original will need to be clamped for several hours. They are similar in strength but the original is slightly better and will withstand higher temps but I doubt that's an issue in your case.

Both versions are workable with tools you would ordinarily use on cast iron or steel once the epoxy has fully set.

It is amazing how many durable, effective repairs can be made with the stuff.

JB weld is amazing. BUT not as good as a weld. Depending on what the function of that part is, welding os a good option. Welding cast is very hard. if its very porous then it will just be a mess. if not you can probably do it. BUT you probably want to "pre heat" and "post heat" the part with a propane torch to get some heat into the part before doing the weld.

Try jb weld first, if that fails, clean it off and weld it. Consider brazing it too, thats sometimes a good option.

Thanks for the replies!

There is no option to weld this as the part I have to repair 'lost' a piece. I was thinking more of sculpting the missing part but I don't think I could do that in five minutes.

Hmmmm... maybe sculpt a 'bridge' piece out of some type of clay and a JB quick weld 'build up' around it might be an option....

BTW This is part of the hand crank mechanism on an 1890 Singer sewing machine. This is an original part. I have another similar, but much younger, hand crank that I could use as a model. The entire piece that is missing is no longer than 5/8" x 3/8 wide.

Shari

There are some two part epoxies out there that come as clay like sticks that you knead together.
One type is marketed for fuel tank repairs and sold at auto supplies. An epoxy of this type might work well for you.

Auto parts stores have this epoxy putty, usually have "steel" in the name. You kneed it together and it is a putty so pretty easily formed. It is also rock hard when cured.

Hi Shari, Can you post a picture some pictures. Just maybe I could duplicate. Remember I have this old machine shop here on the north side of town. Got an old Singer treadle unit sitting up on a shelf here in the shop, it was my Grandmothers use to use it quite a bit. I looked it up awhile back but now I can't remember its apx age other than being from the early part of the 1900's.Gotten lazy and opted for one of them new fangled electric ones with a auto needle threader on it. ( sure saves my bacon). Before you mess it up with epoxy might be able to build it up with brazing material. Once that stuff is on there can't make metalic repair. Chris

Gosh & golly gee - sorry not to have replied earlier! It seems I don't always get notifications of replies to my postings.

Let me get the camera out tomorrow and I'll take some pictures.

PS to Chris,

If your granny's treadle needs an appreciative new home I know of a nice place in the Milwaukee 'burbs.

HI Shari, One of the gals next door has already got dibbs on it, she stops in about once a week to see if its still 20 feet above the floor.