What kind of heat do I need for optimum broken bolt/stud in an aluminum head? Is propane hot enough?
What kind of heat do I need for optimum broken bolt/stud in an aluminum head? Is propane hot enough?
It's my understanding that MAPP is no longer available, instead it's MAP-Pro, which burns at 3730F vs propane at 3600F. At that temp, 130F doesn't seem like much of an advantage. I've also never had MAP help me out where propane failed. I'd probably step up to two propane torches before I went MAP.
If I wanted to go hotter than propane I'd just step up to oxy acetylene which gets you up over 5000F. I find it's also easier to pin point a location with oxy so you can heat exactly what you want. I can also just borrow the torches/tanks from my Dad so it makes it that much easier/cheaper.
I’ve been thinking about OA. Wonder what I cheap (grassroots) set up costs
In reply to ebonyandivory :
Craigslist!
A couple years ago I got 5 tanks, 3 sets of gauges and 5 torches for $250. I kept the best for myself and I sold enough extras that more than paid for the original purchase and I still have a few torches left.
The problem is going to be dumping heat into the head faster than it dissipates it. Small torches don't work very well for that. For large chunks of metal I usually use a weed burner with propane.
They are cheap and put out a bunch of BTUs quickly.
Propane for this job is gonna suck unless you leave the head inside a propane grille for an hour first.
I’m just trying to heat the relatively small area around the stud, no?
Weld a nut on the stud, far and away the best approach.
93gsxturbo said:Weld a nut on the stud, far and away the best approach.
This. A thousand times this.
02Pilot said:93gsxturbo said:Weld a nut on the stud, far and away the best approach.
This. A thousand times this.
Two out of five I can. The other three... not so much
In reply to ebonyandivory :
If it's a choice between the two go with MAP. The higher temperature will give you a higher rate of heat transfer meaning you will get more heat into the same area in a shorter amount of time giving you a better chance of success.
ebonyandivory said:I’m just trying to heat the relatively small area around the stud, no?
The problem is, heat moves through aluminum very quickly. It makes it difficult to get a small area hot enough to do any good without dumping a bunch of heat into it. That's hard to do with a small propane or mapp gas torch. You need enough btus to add heat faster than the head can dissipate it. That will depend on where in the head the stud is and how much mass is around it.
In reply to Toyman01 :
It’s a finned air-cooled aluminum head. Probably the worst for keeping heat in the area.
If bolts are broken below the surface, what’s the GRM trick then? Or is it the ol’ center punch and drill procedure?
Center punch and a reverse drill.
Toyman01 said:Center punch and a reverse drill.
A YouTube video I watched said the biggest issue with left-handed drill bits was that the operators were forgetting to put the drill in reverse!
In reply to ebonyandivory :
That sounds like something I would do.
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