Windy Miller
Semi-Professional Potterer!
- Messages
- 3,493
- Location
- North Kent, UK
A bloke came round today to look at a Blackbird that I have for sale. When I rode it out to the drive, we both noticed a few drips of oil coming from under the engine. Straight away I knew what the problem was - one of the steel pipes feeding the oil cooler had rusted through. Typical Blackbird stuff.
Now the REALLY annoying bit. The pipe has a flange where it joins the alloy engine block that is secud by a couple of tiny m4 or m5 bolts. Normally with plenty of heat I can undo these bolts without too much hassle, but today I managed to snap off one of the heads. Why did they design it with such small bolts? They were always going to snap after a few years of corrosion. Bl00dy stupid idea.
Anyhow, I have to fix it, so the plan is to remove the flange (either by snapping the other bolt, or more heat) and then try to remove the rest of the broken bolt. I had thought of building up the broken end (at the moment about 3mm protruding) with some carefully applied Tig weld, and then popping an m8 nut over the end and gradually filling it up with more weld. My theory is that the heat of welding will help to free off the broken bolt, and the m8 nut will give me something more meaty to grip and hopefully unscrew it.
Now to my question - I have 1.6 and 2.4 tungstens, and 1.6 and 2.4 filler wire. I'm guessing that 1.6 would be best? But what sort of current should I be thinking of? I've got very limited experience with Tig but I reckon I can hande this, just not sure about setting the machine up. Also would a grey tipped tungsten do the job?
Sorry for the lengthy post - just wanted to provide enough background info!
Now the REALLY annoying bit. The pipe has a flange where it joins the alloy engine block that is secud by a couple of tiny m4 or m5 bolts. Normally with plenty of heat I can undo these bolts without too much hassle, but today I managed to snap off one of the heads. Why did they design it with such small bolts? They were always going to snap after a few years of corrosion. Bl00dy stupid idea.
Anyhow, I have to fix it, so the plan is to remove the flange (either by snapping the other bolt, or more heat) and then try to remove the rest of the broken bolt. I had thought of building up the broken end (at the moment about 3mm protruding) with some carefully applied Tig weld, and then popping an m8 nut over the end and gradually filling it up with more weld. My theory is that the heat of welding will help to free off the broken bolt, and the m8 nut will give me something more meaty to grip and hopefully unscrew it.
Now to my question - I have 1.6 and 2.4 tungstens, and 1.6 and 2.4 filler wire. I'm guessing that 1.6 would be best? But what sort of current should I be thinking of? I've got very limited experience with Tig but I reckon I can hande this, just not sure about setting the machine up. Also would a grey tipped tungsten do the job?
Sorry for the lengthy post - just wanted to provide enough background info!