Can I bend a steel trigger guard with a propylene torch?

[Dwshotwell]

I need to bend a steel trigger guard in two spots to conform to the stock. Tried with my basic propane torch and couldn’t get enough heat, which probably surprises nobody. I’ve been trying to figure out the options short of buying a whole welding rig, as I just don’t anticipate doing a lot of metal work going forward. Looks like MAPP gas is no longer available or being phased out. Would propylene be hot enough?

[Wingshot]

Don’t know about the availability of Mapp but I use it quite a bit. I get mine from Plumbing Supply houses. Home Depot usually has it too.

[Dwshotwell]

Ok, it looks like “MAPP” has been phased out but MAP - Pro, which appears to be what I was seeing just called Propylene in other places, has replaced it. I can give that a try.

[Daniel Coats]

Heated or not your trigger guard will want to bend at the point of least resistance. This is governed by thickness or width or both. Everybody knows that already but it's something to keep in mind when planning the bend when needed.

[smart dog]

Hi,
You might try one of the Bernzomatic high swirl tips that tend to mix air into the stream creating more heat.

dave

[Bob Roller]

We have a big hardware store here and no Mapp gas anymore. I never used it but used to see it there.I use a plumbers torch,Presto-Lite tank and it does all I need from making springs to case hardening triggers and frizzens.I was told by "Eks-Spurts" my methods can't work but nearly 60 years of success says they are off base.Mapp gas may still be sold in some areas but I would say that when they are sold out
then it's over and done.
Bob Roller

[Mike Brooks]

I have always bent them cold.

[Dwshotwell]

I tried cold bending it and felt I was on the verge of breaking it. Maybe it can take more stress than I realize but I felt like I was pushing my luck.

[B.Barker]

I have no idea what the cast steel hardware is made from but sounds like it's mostly junk left overs. That is one reason I prefer to make my own. It helps if you have a forge but trigger guards and butt plates can be made without one. Just takes a bit of thinking it through. You can use hot rolled steel which is much easier to work and file.

[P.W.Berkuta]

Years ago (mid 60's) I purchased a plumber's torch set-up along with an aluminum tank for heating/soldering. This setup with different size nozzles was fine for a year or two then I needed more heat, so I purchased a Victor oxy-acetylene welding and from that point on I never had the need for anything else. I used Prestolite gas in high school shop class, and it does well for heating and brazing but not for welding. Prestolite is a one tank system I like the versatility of oxy-acetylene.

[Daryl]

Hi,
You might try one of the Bernzomatic high swirl tips that tend to mix air into the stream creating more heat.

dave

Mapp gas nozzles on propane do add a lot of heat to simple propane. They/it is what I use for high temp silver soldering.

[Carl Young]

Build a fire out of sticks from your yard (or whatever is handy) and let the guard get to a good and dark red heat, then bury it in the ashes overnight. It will be annealed and as soft as it will ever get. If you do have "junk iron" (alloys are usually impurities for our purposes) it may not anneal well and you might have to apply heat to bend it. A few dry bricks (firebrick if you can find them locally) for a small forge, some lump charcoal for fuel and vacuum cleaner/leaf-blower exhaust for blast and you can melt small quantities of whatever iron/steel you may have.

Carl
"Old Jake Dickert didn't have no propylene torch!"  [RIP JerryWH]

[Scota4570]

I bend them cold.

Unless It started as a pretzel, you don't need to bend it much.  Is it some sort of super hard brittle alloy?  It should bend under reasonable pressure. By that I mean captured in a padded vice and bend by hand.   If heated in one spot it will tend bend in that spot. That may make a kink.  I have no idea your particular situation.     

[G_T]

If you can't get the steel hot enough to bend, you can still get it hot enough to anneal it. Get it hot, and slowly cool it. Not hot enough to harden it! And absolutely do not quench it. Let it cool SLOWLY. Then it will be easier to bend. I can't tell you whether it will break or not. That depends on your steel and how much bending you try to do. You can perhaps bend a little, then anneal again... I've done trigger guard reshaping that way.

If it's critical, perhaps waste the money getting a second one. Test on one of them. If it works, you are done. If not, you have learned what you can't get away with. If it almost works, perhaps the second one will work with more care.

Gerald

[kutter]

You can buy a small tank Oxy/Acetylene torch set for not much money.
$300 and under. Not a 'Pro' quality for big boy work but for this type of stuff it's is great.
They have the small tanks that are easy to handle. A torch with a few different tips.
For heating & bending jobs, brazing, gas welding parts & repairs (with some practice of course), high temp silver soldering, and quite a few jobs around the shop and house not gun related,,I've found the small outfit very useful.

The propane torch hardly gets used at all except for the small soft soldering jobs. Just not hot enough.

You can heat an entire trigger guard or other large part like a butt plate casting to red heat in no time and easily bend it to most any shape you want.

I cut off a couple chain link fence post below ground level the other day for a neighbor that refused to be pulled out. No need for the cutting torch head with thin stuff like that and a rough cut being OK.

[Dwshotwell]

Thanks folks. I bought a bottle of MAP/Pro gas today and if that works it’ll be a cheap fix. I also hadn’t understood the annealing process mentioned above, and that may be all I need to do. Worst case, I’m not afraid to order a new one if I do break this one. I did see the small Oxy/acetylene setups - the one I saw was more like $350 but still not horrible if I get it in my head I’d use it. However, I think I might get more use out of a small propane forge and could go that route for less. Up until this, the only use for a torch I’ve had was the occasional small plumbing job, but like most things once you have the tool you tend to find more things you can do with it.

[alacran]

You can make a propane forge for about $50.00. Mostly the cost of the burner, regulator, hose and refractory material.
You can get steel up to critical temp in no time. Or you can get one of those weed burning torches at Harbor Freight and ,  some fire bricks and make a temporary forge that way. Way cheaper than Mapp gas. I use the small Mapp torch for high temp silver soldering.

[Van]

Thanks folks. I bought a bottle of MAP/Pro gas today and if that works it’ll be a cheap fix. I also hadn’t understood the annealing process mentioned above, and that may be all I need to do. Worst case, I’m not afraid to order a new one if I do break this one. I did see the small Oxy/acetylene setups - the one I saw was more like $350 but still not horrible if I get it in my head I’d use it. However, I think I might get more use out of a small propane forge and could go that route for less. Up until this, the only use for a torch I’ve had was the occasional small plumbing job, but like most things once you have the tool you tend to find more things you can do with it.

   The small Bernzomatic Oxygen/Mapp Pro torches are about $75. on Amazon.  Lowes where I got mine is out of stock right now.  Mapp Pro is not quite as hot as the old Mapp but with the oxygen cylinder type torch model it will heat hot enough to braze weld.  I can heat a frizzen or other parts non-magnetic for quench in just a few minutes so it should have no problem heating enough to bend trigger guards. 

[Birddog6]

If it is Investment Cast all these parts ML venders sell, it will not anneal.  Heat it red hot & bend it, and as one said, it will try to bend at the weakest point.

If it is a very Thick guard you may bend it a little while cold. The they break too eash for me to chance, I heat all of them I bend. Same for investment cast brass.

Now if it is a thin TN triggerguard, you best be very Careful, it will definitely break. And that really thin railed one Drew used to sell, you will most likely break it anyway, as they are full of voids & etc. I sorted thru 24 of them on day that Tip had every single one of them had casting flaws. He said they were all that way & Drew was the only supplier. Ordered 4 from TOW, sent them back as same defects. I got so aggravated with them I just made forms & make my own now most of the time.

[bama]

I don’t recommend cold bending, sometimes you can get away with it once or twice before it breaks, but why chance it. I use a Mapp torch and sometimes two of them to heat the piece to bend, I try to keep the piece in the heat while bending if possible.

[Jim Kibler]

Thin steel castings can be hard if not cast well.  I wouln't state this is the rule, however.  We use a couple of the biggest foundries that specialize in muzzleloading parts and in the time we have been making kits, we've only had a batch of maybe 100 or so that were hard.  This is out of many, many thousands.  We routinely straighten buttplates and guards without any heating whatsoever.  So, my position is that as a rule it isn't necessary.  If I had a part of unknown source, I would try to bend it, if it didn't give properly then I might go to a torch. 

For all those who need to tweak our castings, there is absolutely no need to heat anything.

Jim

[Jim Kibler]

Oh, even hard castings can be annealed if held at temperature long enough and cooled slowly enough.  If you don't have a heat treat furnace the wood fire or charcoal trick works well.

Jim

[P.W.Berkuta]

Thanks folks. I bought a bottle of MAP/Pro gas today and if that works it’ll be a cheap fix. I also hadn’t understood the annealing process mentioned above, and that may be all I need to do. Worst case, I’m not afraid to order a new one if I do break this one. I did see the small Oxy/acetylene setups - the one I saw was more like $350 but still not horrible if I get it in my head I’d use it. However, I think I might get more use out of a small propane forge and could go that route for less. Up until this, the only use for a torch I’ve had was the occasional small plumbing job, but like most things once you have the tool you tend to find more things you can do with it.

Stay away from the "MC" size tank they are too small to be useful. You will be running back often to get it refilled. The smallest I would go is a "B" size tank for the acetylene tank which holds about 40 cubic feet of gas or a "WQ" size which holds about 60 cubic feet. If you don't do a lot cutting then you don't need a lot of oxygen so you can get away with about the same size (cubic feet) of an oxygen tank as the acetylene tank<https://gendco.com/downloads/cylinder-size-chart.pdf>
A rosebud tip is great for heating up stuff and a Victor size 100 torch handle is a good hobby size for most home garage work with three tip sizes from "0" , "#1" and a "#2" to start with. That should cover 3/32" to maybe 3/16" steel welding. If brazing or silver soldering you can do much thicker steels with those tips. Hope this helps

[Scota4570]

I have annealed files by putting them in the BBQ coals and letting the files get very hot then cool naturally overnight.  It is also an excuse to grill something too!

[Dwshotwell]

Thanks for the ideas. With some experimentation based on this I'm sure I can get it done.

DS