Torch options

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

cfellows

Well-Known Member
Project of the Month Winner
Joined
Aug 25, 2007
Messages
3,890
Reaction score
715
I've been wanting to get started on a boiler for my double acting twin oscillator for some time now, but I'm stymied by what to use for a heat source. The boiler will be 3" diameter x 6" copper pipe with a 1.25" copper flue. I have a mapp gas handheld torch but I don't believe that will provide enough heat. I'm reluctant to spend $200 or more on a Goss or Seifert propane torch head. I also have an oxy acetylene torch with several different brazing tips but feel like that will heat that is too concentrated.

I'm wondering if a heating nozzle tip with a diffuse flame for the acetylene torch would be satisfactory or what other options might be available to me.

Chuck
 
If you have an OA set up already, check out a Rosebud tip. It's meant for less concentrated heating than the typical welding tips. Also, get some fire brick and build a "hearth" to help keep the heat in the work. I have found this to be very helpful.
 
Hi Chuck. I would give the Mapp gas a try. The " Backyard metal casting site" uses Mapp gas for melting iron. They describe Mapp gas as
MAPP® gas (C3H4) is produced by combining liquified petroleum gas with Methylacetylene-Propadiene. It can produce close to the heat of acetylene but is as safe to handle as propane. A neutral MAPP gas flame is 5,301° F. (2,927° C.)
Nearly 3000 deg C I think is worth a try. Good luck.
 
Hi Chuck,

As I don't have access to Oxy/Acetylene the good old fashioned kerosene blowlamp will give widespread background heat to the barrel whilst the delicate work is done with the mapp gas. The rosebud tip for your oxy should also suit your needs but needs to be run fairly low with a neutral flame and kept away from the barrel so the heat will spread.

Hope this helps

Best Regards
Bob
 
Just use a cutting tip in the o/a torch and keep the inner cone of the flame well away from the work - using only the outer envelope. Neutral flame, as Bob said and keep your finger right away from the oxy button.
 
Over here Chuck, we tend to stay clear of oxy/acet unless for very large items, and tend to stick with propane burners such as these.

http://www.machinemart.co.uk/shop/product/details/fc108-gas-torch-with-nozzles

A couple of these will even silver solder up a largish loco boiler.

In my early days, I used to make steam plant boilers like that you are making with a couple of plumbers torches, similar to these. One smaller for the flowing of the solder and a larger one for background heat.

http://www.machinemart.co.uk/shop/product/details/jetline-gas-torch


John

 
Thanks, guys, for the advice. I'm considering a rosebud tip for now. Anybody know what size I should get? Would a Victor 8-MFA be about right?

Thx...
Chuck
 
Chuck,
The propane advice is good, and best, however I understand not wanting to invest in a new system for one boiler. I have a Victor rosebud tip #6-T-29 which is from a torch set (ca1975) and may no longer be a valid number. It's a 5/8" diameter tip and I used it for a number of years as my principle boiler torch, now replaced by larger propane gear. It will of course do the job but even throttled back and diffused it throws out a lot of heat.
 
I use a Mappgas torch set, an oxygen/propane/butane set, and an oxy-acetylene but the latter is the fastest and most efficient.
I'm working with very high-temp siver solder so I need very hot flame. 8)
 

Latest posts

Back
Top