JB Weld or what

jmoore65 · Post by **jmoore65** » Thu Nov 11, 2010 12:46 pm

I would worry a bit about the difference in expansion/contraction properties of the aluminum and the filler material.

JPG · Post by **JPG** » Thu Nov 11, 2010 1:13 pm

jmoore65 wrote:I would worry a bit about the difference in expansion/contraction properties of the aluminum and the filler material.

Don't worry about that, it is always hot in Tucson!:D

I think wood would work as well as being easier to work with.

charlese · Post by **charlese** » Thu Nov 11, 2010 9:37 pm

The JB Weld Co. says engine blocks have been repaired with their product, and are working for years. I wouldn't worry about expansion.

Ed in Tampa · Post by **Ed in Tampa** » Fri Nov 12, 2010 9:46 am

There is a product I don't know the name of that is an epoxy that comes in a two tone roll that you knead together and use. I have used that and JB weld (Which is another epoxy) and have had excellent results.

If this were mine I would do as Dusty's last post states, if filling the whole area would not effect the use, I would flood the area with JB Weld and not worry about the problem anymore. I would rough up all the surfaces so there was good physical bonding and I would clean and reclean the surface before I applied the JB Weld. I might even consider drilling a few holes at the end of the cracks and possibly elsewhere to give the JB Weld a place to bond to.

I have never seen a failure of JB Weld (the product itself) but I have seen failures where it failed because it didn't bond properly to a surface. I contributed every failure to contamination (oil or something left on the "to be repaired" surface.)

I wood not use wood as a filler.

dusty · Post by **dusty** » Fri Nov 12, 2010 12:31 pm

It is now too late for me to benefit from your advise, Ed, but I would still like to hear why you would not use wood as a filler in that hollow space.

As you can guess, I have done just that. I crafted a piece to sorta fit in the space. Drilled a hole where the spring needs to go and installed that using JBWeld to fill all the gaps.

It looks and feels solid to me and I don't have to spend any money (at least right now)..

Ed in Tampa · Post by **Ed in Tampa** » Sat Nov 13, 2010 11:17 am

Dusty
The biggest reason is the bond between the wood and the JB Weld is another point of potential failure. The biggest problem I have seen with JB Weld or epoxy for that matter, is the breaking of the bond where it meets the other material.

I have used JBWeld in many applications and I'm almost always astonished by its physical strength. And as I stated in my other post the only real failure I have observed was where the JBWeld broke bond with whatever I was repairing. Also as I stated it was usually a user error where the bonding surface wasn't sufficiently prepared.

If the wood is totally encased then there probably isn't any bonding problem. But I probably would have used extra JBWeld and made it a solid mass instead.

Best to ya!

Stitch · Post by **Stitch** » Sat Nov 13, 2010 12:17 pm

Thanks for the feedback, Ed. I think we are okay on this. The wood that is there is only there to occupy space. It is bonded into that space but the JBWeld actually provides for 1) the repair of the crack and 2) building up the back to where it meets the wood block.

I also used JBWeld, applied to the inside of the casting, to entrap the wood so that it can not move out of position.

I have confidence that it will now last as long as I will and then some.

If it does not, I'll just have to break for the cost of a new headrest.

Again, thank you for the feedback.

dusty · Post by **dusty** » Sat Nov 13, 2010 12:42 pm

I'm too cheap to use that much JBWeld just to occupy that open space, Ed.

I epoxied a block of wood that had been sanded down to fit into the space behind the crack. I then forced JBWeld into the cracks and formed a JBWeld bridge to the far side of the open space. It is good and solid and blocks the cracked area from moving under pressure from the headstock lock.

I think I am back in business.

robinson46176 · Post by **robinson46176** » Sun Nov 14, 2010 4:40 pm

While that part was probably badly over-tightened by a PO the actual needed pressure at that point is fairly minimal and with your careful setting of that adjustment it is unlikely that you will have any problems from that repair.

dusty · Post by **dusty** » Sun Nov 14, 2010 4:46 pm

robinson46176 wrote:While that part was probably badly over-tightened by a PO the actual needed pressure at that point is fairly minimal and with your careful setting of that adjustment it is unlikely that you will have any problems from that repair.

I will be giving it a workout so we won't have to wait long to see if it holds. I am impressed with the characteristics of JB Weld. I had never used it before. Hope it holds as good as it looks.