Tigging down a hole

[northwest]

So, I have tackled this a couple of times:

The job I have to do once in a while is put a bit of weld down a hole as a "tamper proof lock". I first drill a hole, counter bore it, tap a short piece of bar (wire really) down it and have to put a blob of weld at the bottom of the hole to lock it in place. The snag in this procedure is the hole is about 5mm across and about 4 to 6mm deep, it varies.

I am struggling to get the bottom of the hole hot enough to melt the wire, i am trying to fire the arc down to the bottom of this hole. I always have a couple of goes on a trial piece before actually executing the task and so far I have been okay but the last time I had to dwell on the wire a bit to get it to melt fully and actually look like a weld, the job became really hot. Should I be looking for a smaller torch? I am using a WP17 at the mo.

 

[gordon stephenson]

Cant you use Mig?

 

[Brad93]

Are you using a gas lens? Down a hole you can stick out the tungsten a good 15mm and keep gas coverage. Might be easier with a smaller torch but should be possible with a 17 no problem.

 

[northwest]

Cant you use Mig?

I think that on the end of a gun barrel a bit of Mig might just stick out like a sore thumb. Any spatter and the finish is done for and missing the target just doesn't bear thinking about. It was relevant and I forgot to mention that, sorry.

 

[Migmac]

Graham, did you watch the video that someone posted about getting stuck bolts out using a mig and copper tubing to protect threads? Could you adapt that method to do your job?

 

[Shox Dr]

I would set the tungsten at the correct height down the hole, maybe machine a collet to hold it centra, and give it a zap. Build a test piece to refine it

 

[northwest]

Graham, did you watch the video that someone posted about getting stuck bolts out using a mig and copper tubing to protect threads? Could you adapt that method to do your job?

No, I didn't see that, what a good idea. I feel another Jig coming up.

I am using a gas lens Brad but thought anything more than 5-6mm stick out was not good. I will try that too.

 

[Brad93]

No, I didn't see that, what a good idea. I feel another Jig coming up.

I am using a gas lens Brad but thought anything more than 5-6mm stick out was not good. I will try that too.

Stick it right out mate just get a bit of gas flowing to purge the hole out before you arc up.

 

[northwest]

I will drill a couple test holes tomorrow on a sacrificial, have a few goes and report back. Thanks for the suggestions.

 

[Migmac]

This https://www.mig-welding.co.uk/forum/threads/just-seen-this.109461/unread