Tapping into boiler

Ive just drilled my 7ba pilot hole too deep and gone straight through the boiler wall. Ibe tapped 7ba and coated the bolt threads with bearing lock (weak loctite), should this be enough to stop it leaking?

At room temperature, probably, but at steam temperature, not likely. If it were me, I'd drill it out (and all others like it) and fit bronze bushes silver soldered in place.

Many designers of model engines specified tapped holes into the boiler shell for attaching things, Martin Evans in particular, even if only two full threads would be possible. Just not good practice. A boss through, or a tapped lug soldered on the outside of the shell under cleading is a much safer method.

JD

Steel boiler Fizzy? Weld the hole with MIG?

I can easily weld it but didnt want all the hassle of prepping into 6mm steel. I would tig it to be sure of penetration, but then it would be a pig to redrill and tap.

remember its only 7ba

Can't you drill it out to say 1/4" prep and weld in a pre tapped blind bush made from a bit of 1/4" rod.

J

Edited By JasonB on 06/11/2012 18:21:27

hi Jason - not a chance. The amperage required to get good penetration would obliterate the bush for sure. Im gona take my chances with the loctite, its screwed in pretty tight so even if there is a small initial leak it wont be long before it gets filled with boiler gunk and blocks up! (tiny fragments of rust etc).

Hii Fizzy is it still pink??

Why not silver solder a bush in.

Steve Larner

Sorry to hijack the thread, but I have a similar problem with a misplaced 1/8" hole drilled through a copper boiler. Could anyone advise if it would be safe to use a 1/8" solid copper rivet to fill the hole and then silver solder over it after it was fitted? If it makes a difference its a 3 1/2" gauge northumbrian boiler if that makes a difference.

Dave

that will be fine