Thermostat bolt broke

Smagu · 16 June 2021, 20:10

Had a bit of a nightmare checking my thermostat (it works fine should have left it)

Bolt broke off then when extracting the bolt it broke the ear off the casing…

I’ve tried drilling and tapping chemical metal, note onto a piece of threaded bar. Anyone got any ideas?

Limecc · 16 June 2021, 20:38

www.amazon.co.uk/Durafix-Aluminium-Welding-Easyweld

https://www.youtube.com/watch?v=n1njyuPBIH0

Smagu · 16 June 2021, 20:44

Quote:

Originally Posted by Limecc

https://www.youtube.com/watch?v=n1njyuPBIH0

These look really interesting must look into them!

Limecc · 16 June 2021, 20:51

Added a link where to buy. Do let us know how you get on.

Smagu · 16 June 2021, 20:54

Thanks. I’ll try to see if the bolt with a screw through it and metal epoxy works tomorrow. If not this will be the next steep. I wonder if I’m better trying to fix the bolt in or drilling and tapping

Limecc · 16 June 2021, 22:55

Quote:

Originally Posted by Smagu

Thanks. I’ll try to see if the bolt with a screw through it and metal epoxy works tomorrow. If not this will be the next steep. I wonder if I’m better trying to fix the bolt in or drilling and tapping

Weld it up with those rods, drill and tap. Worth it in the long run, why bodge it again?

wgc851 · 16 June 2021, 23:01

Quote:

Originally Posted by Smagu

Thanks. I’ll try to see if the bolt with a screw through it and metal epoxy works tomorrow. If not this will be the next steep. I wonder if I’m better trying to fix the bolt in or drilling and tapping

I would try gluing a stud in and then secure the cover with a nut

Smagu · 16 June 2021, 23:08

Tried a nut can’t get it in due to the inset of the hole.

I’m debating placing a large pipe clamp/ work screw on it too to hold it together. If it’s leaking abit is it such a big issue for a few weeks? It’s been away for 7 weeks for another issue so just want to get out on it

trevbouy · 17 June 2021, 08:50

That's cast alloy. Only real answer is tig weld built up to allow re-tapping.

I had same issue and local welder built it up ok.

One warning, remove ignitor/ignition. I know because I assumed mine was magneto, it wasn't and it's now fubar.

paintman · 17 June 2021, 19:03

Having used them I can say that those rods do have their uses but you need to get the thing they're going onto up to the right temperature.
If it isn't they will just break up & not adhere as you can see at 1.20 in the links.
The problem you've got with an engine is that you're trying to heat up a giant heatsink & you aren't going to achieve that with a diy blowtorch.

I've had a number of threaded holes & broken bosses on old British bike engines successfully repaired by welding them up - mig or tig - then drilling & tapping.

paintman · 17 June 2021, 19:30

If you wanted to retry gluing a stud with JB Weld or similar then you could try drilling the stud & putting a couple of short pins in to help lock it with the glue to stop it turning.
Cutting a slot at the glue end with a 1mm disc would probably work just as well

The metal you are trying to glue it to needs to be squeaky clean!

If you can't get a nut on the stud due to clearance issues just use a load of washers before putting the nut one.

Limecc · 17 June 2021, 21:52

Quote:

Originally Posted by paintman

The problem you've got with an engine is that you're trying to heat up a giant heatsink & you aren't going to achieve that with a diy blowtorch.

Yes I think it would require oxy-acetylene for sure. Maybe oxy-propane.

Smagu · 19 June 2021, 17:24

So I got the problem somewhat solved. The epoxied treaded bar didn’t work. Epoxy cracked. Managed to use a grinder to make enough of a gap and an edge. Got a nut in place then tightened down. Works well and it doesn’t even leak a drop. Doesn’t look pretty. But it’s solid! Thanks for the advice. I talked to a few engineering places. They all wanted the engine broke down and stated it would be a sketchy job and might not hold a tap well!