Would you repair an Exhaust Stud With JB Weld?

[rxe]

Our guy drilled them both out, filled them with the low temp rods and milled the face back to original.

Did he form the threads from the filler rod? The HTS people have got a neat video of a bloke immersing a steel bolt in a pool of filler and "casting" the thread. In their video it seemed strong, but you never know how real these things are. I think filling up the hole completely, then drilling a timesert in properly may be the strongest.

 

[Dan Forsh]

I'm not 100% as he took it home to do, but I think he filled the holes completely with the rods, milled it flat and then drilled and re-tapped the threads.

Maybe his technique was lacking as it just looks to me as though the welds didn't really bond with the cylinder metal.

I can't complain as he did it as a favour, so I'm thankful for that. But I know the feeling you have, it really riles you when you have a good cylinder, but can't use it for something as simple as a bust exhaust thread.

 

[rxe]

It lives, Igor, it lives!!!

Here's an update - I've done the first version of the repair, we'll see how long this lasts. I ordered up the HTS-2000, and it arrived quickly. So I went down to the garage and broke out the heating gear.

From left to right, just like the three bears: too cold, much too hot, just right:

Let's be really clear up front: the guy in the HTS-2000 video is an artist. Using this stuff is harder than it looks. The best method seems to be making a steel mould (out of 1 mm sheet) to retain the liquid "solder", heating up the lug, and flooding the area with solder until the mould is full. Leave to cool, take off the mould, then get busy with the file. The result is, well, ugly, but it holds torque - it is better stuck on than it looks:

If it snaps off, then I will just re-do it - hopefully my skills will have improved by then. This saw will probably end up being the powerhead for the Lewis winch I am planning on getting, so it will see some action. I still need to find an exhaust for it.....

 

[Lakeside53]

Good job!

 

[monkeyboi]

If it happens again try MAPP gas or Turbo torch with acetylene. I have used those rods on an aluminum canoe & found oxy/acetylene way too hot & this was with my little refrigeration torch. I tried propane but found MAPP to be WAY easier to work with. But those rods are neat for that kind of job & a lot easier to build up material than with TIG.

 

[user 19670]

I would drill/tap it out and put in the correct size steel TIMESERT insert with red loctite. The crack won't matter when the insert is in place. If the hole is too big, drill it out, tap it with any coarse thread, make an aluminum 6061 plug with the same thread, insert with red loctite, then drill out and retap to orginal. Sounds like a lot of work, but it's not really.. maybe an hour or two of messing around...

500F with JB.. well.. they may claim that, but above 300F or so it's getting soft, and at 500F it will fail completely - not melt, but fail chemically.

Loctite don't like it hot either. Heat destroys it and allows you to disassemble easily. Aluminum is easily weldable (by those with the skills) and this can be welded up, re-drilled and taped to make a repair that will be as good as new.

 

[Lakeside53]

I've had good luck with the high temperature version of red loctite in that position. But yes, heat it enough and you can break it down.

 

[Stihl 041S]

Danger Will Robinson

Having to do with the title of this thread:
do not know if it has been said, JB Weld to 500 deg F,however the 4 minute stuff from JB Weld is for 200 deg F Max.