Welded Jugs 088

[Rotax Robert]

Rotax here, I have a 088 walkerized,greffardized and K.D. all rolled into one. Take note that this probably the most expensive hotsaw in the world since most everybody has worked on it. Now for the ?

The ears that the muffler/pipe connect to with the wedges and spring are getting chipped off making it difficult for the pipe to stay on ( the muffler stays on fine) but the pipe comes loose in racing situations. Yes it is supported by two different staps also in addition to the wedges and spring. Can this jug be safely welded on without hurting or warping the jug? I have a welder buddy who is a master welder on aluminium.

Rotax Robert

 

[NWCS]

should weld up fine as long as the temp is kept low, and the weld time kept low also, just keep tapping at it. i would think just going at it all at once would kill the plating. i never understood why the 088 does not have a bolt on muffler like the 084. the clamp system is just odd in my mind.

 

[RaisedByWolves]

I dont think temp will be the biggest problem in this case. We do a fair share of repair work where I work and have found that cast alu, especially cast that has been abused (pounded, oil soaked, dirty, etc) is more troublesome than regular billet items.

Castings tend to be porous and hold a lot of junk under the surface. We will sometimes heat the part to be welded to about 400-500 to cook off any impurities.


Weather you want to do this with your cylinder or not is your baby, but if you do heat it, heat it in an oven,NOT with a torch.

As a matter of fact you cound lessen the chance of warpage greatly by preheating it to around 300 before welding.


Hope this helps, Eric

 

[timberwolf]

TIG or Plasma to build it up slow, with the right equipment the heat could be kept in the torch as much as possible by manipulating wave control.

 

[ehp]

Rotax you could always machine the ext.port out and put a aluminium block in its place that is held in by screws that bolt the block to the fins on the jug. I have had the same problem with the 088/880 even on muffler they always seem to break the one ear off right off the bat

 

[Andy1234]

First, call Stihl and find out what kind of aluminum it is! That way, you know which rod to use. I would guess maybe AL356, but I don't know for sure.
If they won't tell you, and nobody else knows, 4340 is a good General Purpose rod for TIG welding. Maybe find a junk cylinder to experiment with first.
RaisedByWolves is correct, stick it in an oven for several hours and cook the oil and grease out. If your wife/girlfriend has a problem with this , then take it to your local automotive engine rebuilder and/or speed shop and have them hot tank it.
With any kind of welding, prep is the key! Good welds are 90% good prep and 10% operator input. Any dirt, grease, oil or oxides left on the weld area will lead to porosity and weld defects. Again, CLEAN IT GOOD!!
After it is cleaned, grind back to raw aluminum and go slowly. Weld for 30 sec, and let it cool for 2-3 minutes, repeat as necessary.
Good Luck!
Andy1234

 

[Crofter]

Rotax, it was suggested by someone here in the passt regarding bukilding up outside exhaust port to get meat for porting that the way to go was machine a steel plug a thou or so smaller than jug dia. and heat the jug to about 400 F and slip the plug in while doing the welding to keep things true and then heat the jug to get it back off the mandrel. Mig should cause less warping but it sure would be nice to try it on a scrap jug of the same composition because it is a bit of a crap shoot as to how well it will flow out and how porous the deposit will be. I have seen beautifull and I have seen some that nothing seems to do a decent job.

 

[Rotax Robert]

I just happen to have an extra jug that somebody put 187 deg. exhaust into that is pretty much junk and can play with that one first, Just the same keep the comments coming. Thanks for all the input.

Rotax