Can I epoxy resin bolts to secure mantle to cast fireplace?

[reubin78]

We have a cast iron fireplace that is missing the mantle. I have managed to pick up a replacement (salvaged) mantle which I have cut to the right depth.

The problem is......

......the securing bolts are on the scrap part of the mantle. I now need two bolts to fasten the mantle to the fireplace.

I had considered tacking two bolts to the underside of the mantle but only have access to a mig welder (and have read it is problematic) - is it?

Don't want to drill the mantle as the heads (even if countersunk) will show.
E
Have just read that people recommend J-B epoxy resin. Would that work (basically glue two bolt heads to the underside)?

Has anyone tried any of the above and succeeded? Does anyone have have experience in these areas?

Many thanks

 

[Burnerman]

If the mantle is cast iron, then I'm afraid any bolts would need to be brazed in place rather than mig.
Epoxy adhesives are as good as you get, but even they rely on substantial surface area contact to be really reliable.
Would there be any possibility of you fixing the mantle to the wall as well?
John

 

[reubin78]

I could support it with discreet brackets but (as the mantle is essentially smooth underneath) there is nothing to hold it in place. It could be simply lifted off or more worrying fall off if knocked.

 

[Burnerman]

How thick is the mantle, and is it metal?
(Thinking of drilling holes in, to accept threaded studs).
John

 

[reubin78]

Mantle is also cast iron and it's approx 1/4 inch (6mm) thick - so barely thick enough to drill blind holes into/tap.

 

[Burnerman]

I think I'd be hunting down someone with oxy acetylene gear......it's really no problem to braze bolt heads on to cast iron.
John

 

[Dave54]

Brazing is the easiest way to go as John says. I've done it myself in the past.
If what I remember is correct, (and you'd need to check), then I think you could arc weld it with Eutectrode 680s or similar, but I suspect the cast would need preheating, and those rods are pretty expensive. Overkill I'd have thought.
If you're going to get it brazed clean the areas back to bright metal and mark where the bolts have to go.