JB weld/ Devcon product stories and reccomendations

[Dr.Robotnik]

Well, this thread is a continuation from my helicoils thread. Unfortunately I had not assessed the parts I was repairing properly and so it seems I cannot helicoil them.

The reason is that the parts have been stripped to far for the right size of helicoil to work.

For example I have some Altek Magura levers and the M4 clamp bolt is stripped. The previous owner (I guess) then thought to just tap it for M5. Being inexperienced they have drilled a 5mm hole which obviously cannot be tapped for M5!!! :shock: A helicoil won't fit either, so what can I do?

So can I fill the hole with an epoxy metal and then drill and tap the hole again?

If so can you help me picking the right product as I don't have experience with them though I know of the brands JB weld and Devcon.

Am I after the JB-STIK Part No. 8267-S ?

Also if I chose an metal filled epoxy, should it be Aluminium filled as the lever is an Aluminium? Or steel, or titanium????

Totally out of my depth, please help...

Cheers

 

[shovelon]

I work alot with inserts, threadlocker, and fillers. Actually my favorite easy use filler is JB weld, but is too fragile and will not hold a helicoil like you want.

But if the hole is too big for a helicoil, you could use a solid insert like a keensert. They are spec'ed in aluminum structures quite often and they are magic.

This is item number 97120A200. Go to Mcmaster.com and type in the number for a description. The tap size is M8 believe, so see if you have enough material surrounding the hole. If you are in Europe, try to look for them locally.

Good Luck

 

[elite504]

if its at 5mm, that the right soze to tap M6. Other alternative, is to 'through drill, and use a nutsert/ rivnut but not pretty on a bling part
JB weld on a thread you're actually gonna load, forget it. It works ok as does devon for flowing the inlets of cylinder heads and the like, but structural, forget it. . .

 

[Dr.Robotnik]

Thanks guys. I'd read mixed reviews on other sites about those products but couldn't find a definitive answer.

I have brought the seat post in today to show to our technicians and ask their advice. As there is only 2mm on one of the edges of the hole I don't even think tapping to M6 is a good idea, I certainly couldn't tap to M8. I might just revert to having a hex nut at the top of the hole and using an M5 bolt all the way through.

This part isn't bling but it's an early Sunn post and goes on my Radical. So I am just hoping to do what I can...

 

[shovelon]

A few years ago I came across a kit of helicoils called "Twinserts". It was a helicoil within a helicoil for those situations when a standard helicoil could not get a grab.

Unfortunately I cannot remember where to find them. Perhaps a google?

 

[kaiser]

Can it be tapped for an M5 heli coil?

 

[shovelon]

Here is a UK source for twinsert.

https://secure.farsound.co.uk/inventory ... earchtype=

 

[Dr.Robotnik]

Can it be tapped for an M5 heli coil?

No 'fraid not. There is just not enough meat for the helicoil to stay put and it is just pulled out. It doesn't seat properly either.

I will look into twinserts, though, thanks a lot.

Also my latest idea is, I might extend the hole a tiny bit and tap it M4 so there would be 2mm of M4 threads and fill the rest with Devcon as threads. Maybe the combination would hold?

I'll post pics soon as well so you can get a better idea of what I am talking about.