Tool Related - JB Weld Strength

[Scott Coffelt]

OK this is related since I am working on my 6x48 edge sander. I started this last weekend to do some refurb work on an old sander (made 1988) purchased through a fellow SMCer. I disassembled in to clean up and do some painting along with have some missing parts fabricated. Anyways, there is a bolt in the belt tracking unit that was broken (hidden), I could have even busted it when taking apart. I have only begun to reassemble, so I am not sure how much it would effect the task or not. It is a left handed threaded bolt-thingy that has the last 1/2 or so machined down (I'd say almost just grinded down) with a middle portion grinded even more to accept a set screw. Well, it broke int he thiniest section. I had some JB weld laying around and thought I would give it a try. My question is for folks who have used this stuff, how well does it work. The ads say it will be just like new essentially, but can I actually expect that it will hold? My plans are to let it sit for a few days to really harden before reassembly.

If it doesn't, I will have to find the right sized reverse thread bolt and then have it milled to match the existing part. I doubt I could locate a raplacment, not your standard brand name (Mao-Shan is the manufacturer and it is labeled through Wood-tek.

I was just curious about how well JB Weld works.

[Joe Chritz]

Only used it once to fix a metal heating hose in an old mini-van. Used it just as a get-me-by because I was leaving to go steelhead fishing early in the AM. Stayed on for three years or so before I sold the van, still on as far as I know.

Not sure about the bolt holding if it is fixed with the stuff.

It is great for saving a fishing trip though. :D

Joe

edit: I really need a spell checker

[John Lohmann]

I've used it to repair a bell housing for a MGB that hit the floor. It broke off where one of the bolt holes was the repair has lasted 10+ years. I think the metal was aluminum.

[Randy Meijer]

In the right circumstances, JB Weld does a terrific job!!! I have used it many times and been completely satisfied. That being said, I have no idea if it will work for you?? I don't really have a good idea of what you are trying to accomplish from the description you have written.

The success of a JB Weld repair depends primarily surface area available to glue and the amount and type of force that the joint is required to resist.....compressional, extensional. tortional or shear?? Quick answer is try it and see what happens. JB Weld is cheap and you don't have a whole lot to lose. Maybe a few more details or a photo would help.

And I would still try the manufacturer/distributor for a replacement part if you can still contact them. You just might luck out and be able to find a replacement???

[Scott Coffelt]

If I think about it tonight I'll post a pic.

I'd try and explain it, but probably can't do it with much sense. Was just curious as to the strength of JB weld.

I will also check around locally for some metric reverse bolts. I can always grind one down if this doen't work out. Replacing it should be too much trouble if it does break as it's only a couple parts to remove.

[Julio Navarro]

Ive used JB weld on a couple of occasions both have failed. Once reattaching brocken passanger pegs on my bike, they are aluminum but they recently re fractured along the JB weld.

[Wes Bischel]

Scott,
I used JB Weld on a trunnion on my 12" BS - that was 5 or 6 years ago and it is still going strong. With that said, I'm not sure there will be enough surface area for JB. How about a little silver solder? Personally, I would put a little more stock in that than the JB Weld.

FWIW, Wes

[Vaughn McMillan]

Not sure if it'd work in your situation Scott, but as Randy mentioned, it probably won't hurt to give it a try. I used JB Weld to repair a hanger for a pocket door in my last house. The "C" shaped part of the hanger that grasped the pan head screw coming out of the top of the wooden door broke, so I cut a flat washer into a "C" shape, and JB'ed it to the hanger. Worked for several years before I sold the house, and last I saw it (a few months ago) it was still holding.

- Vaughn

[Kyle Kraft]

I used JB Weld to rebuild/retap some pipe threads on the exhaust port of a 14hp lawn tractor engine, and the stuff held for years. I have since sold the tractor to a friend and to my knowledge it's still holding.

[Stu Ablett in Tokyo Japan]

First, there are two kinds of JB weld, a "Quick" and a "Slow".

The quick is not nearly as hard or as heat resistant as the slow.

I've used it to fix lots of stuff, and I've never had a problem.

You can also buy a putty like stuff, the inside and the outside of the putty are two different parts, you knead it together to get one consistant color, and it hardens up in a few minutes. I always have a bit of this stuff with me on my bike tours.

Give it a go!

Cheers!

[Scott Coffelt]

I snapped a couple of photo's this morning. The first is a shot of the bolt, if you look closely you can see the JB Weld. Next are two shots of the bolt in the piece. I think it will hold fine, but only time will tell. I think the key will be how tight the set screw gets set. If you just let it stay a little loose the bolt turns fine and less pressure will be put on the weld. The set crew is to hold it from sliding out anyways.

[Randy Meijer]

Scott, I hope it works for you. If I understand the pictures correctly, I'm not real optimistic. The fact that the bolt broke in the first place suggests a strong force and a relatively weak design. With the gluing surface being so small, I'm afraid the joint may not hold. Now that I see the part, I think it would have been better to braze it. Good luck!!

[Dan Forman]

Can you bore out and re-tap the thingy it goes into, then use a new bolt of the retapped size?

Dan

[Scott Coffelt]

We'll see how this works first. I'll take a pic after it is all assembled, I am not sure there is really any fore on the area of break. The sanding belt itself will force it towards the threads, which is also supported within the metal shaft (probably not clear). Anyways , if it don't work I can either choose to find a reverse threaded bolt that will fit and then mill down or drill out the threads of the piece that part fits in and re-tap for right hand threads and do the same thing. The assembly is used to adjust tracking of the belt, so I really can't see how the direction of thread will make a hill of beans.

[Doug Shepard]

.. The assembly is used to adjust tracking of the belt, so I really can't see how the direction of thread will make a hill of beans.

I'm no expert but the only time I've run into reverse threaded bolts is for cases where the thread needs to be in the opposite direction from the direction of a rotating part so that the bolt doesn't spin out. Is the larger shiny piece the actual roller that the belt runs on? If so, I'm guessing it rotates in the opposite direction of the bolt threads. You might need to stick with the reverse thread if that's the case.

[Wes Bischel]

Scott,

If the bolt does fail, an idea: Grind the threaded segments end flat, center punch it and drill it to fit the broken shaft. Or, tap the hole and use a bolt to replace the broken shaft.

Naturally this assumes the JB fails, and there is enough thickness in the threaded segment to hold it!:rolleyes:

Wes

[Scott Coffelt]

Thanks all, it will be another week or so before I can get back to re-assembling as we haveSpring Break coming up. I'll post progress pics once assembled and tested.

[Rick Whitehead]

If it breaks again, you might try contacting Woodworker's Supply and see if they have a relacement part. They are the importers of Woodtek machinery, and might have the bolt you need.
Rick