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View Full Version : Metal Heating options Mapps kits any good?



joez
27th Apr 2018, 11:17 AM
Im after recommendations for occasional use, I'll probably be using it less than x20 a year.

Mainly to straighten/bend and occasionly harden small pieces. The stuff I work with is normally in the 3-5mm range.


Are these style kits any good?


https://www.totaltools.com.au/89715-bernzomatic-mapp-oxy-soldering-torch-kit-ox2550tk

thanks
Joez

OxxAndBert
27th Apr 2018, 12:07 PM
I haven't used the oxy version, but have a Bernzomatic TS8000 Mapp gas torch. Its definitely slower and cooler than oxy-acetylene, but works OK for heating rod up to about 10mm diam for bending, and I've also bent 30mm wide flat up to 5mm as well as done some small brazing jobs.
I noticed on the spec for the unit you posted that it uses 5 oxy bottles to 1 fuel. Not sure how much the oxy bottles are but if they're anything like the $20-30 for the Mapp gas that could get expensive to run if you're doing much work with it.

Steve

joez
27th Apr 2018, 12:12 PM
Yes it sounds expensive to run, thats why I was double checking. Runnings costs sound high.


• Usage Ratio: Map Gas = 1 Bottle to Oxygen = 5 Bottles
• Oxygen will last 10 minutes on high flame

KBs PensNmore
27th Apr 2018, 11:57 PM
Have you thought about a small forge, a lot cheaper to run at a guess, too.
Kryn

joez
28th Apr 2018, 10:15 AM
Have you thought about a small forge, a lot cheaper to run at a guess, too.
Kryn
forge would be my choice if I had more space :(

onanonanon
28th Apr 2018, 04:11 PM
I used to make knives and other assorted tools using a forge, but found smoke to be a problem. With the fan on smoke is negligible, but once the air is turned off the smoke is copious. I did try charcoal by found it disappeared very quickly. I have also seen BBQ heat beads used.

For one job I used a jam tin squashed in at the middle top to form two spouts, one for air input the other for the flame. It worked extremely well the flame heating metal to red hot in super quick time. Forges do not need to be large, my favourite was 12" long and about 8" wide, made of 1/8" plate welded in a V shape to a tube with holes for air. For air I used a Little Beaver spray unit.and later a vacuum motor re-homed in a purpose built housing.

BobL
29th Apr 2018, 10:20 AM
I used to make knives and other assorted tools using a forge, but found smoke to be a problem. With the fan on smoke is negligible, but once the air is turned off the smoke is copious. I did try charcoal by found it disappeared very quickly. I have also seen BBQ heat beads used.

No smoke problems if gas is used. My setup uses mains gas turbocharged with a vacuum cleaner. The main problems in my small shed were CO levels and sheer heat output. Increasing the ventilation to 2600 CFM took care of the CO problem but I still can't really run the forge for more than a couple of hours because the radiant heat just makes the inside of the shed too hot to work. This is long enough to anneal and harden small bits of tool steel but annealing lump like this in summer (http://metalworkforums.com/f266/t168547-building-natural-gas-forge-wip/page-3#post1887519)pushes things close to the limit. Its fairly cheap to run, in one of the threads in the BS forum I said it cost about $3/hr but it's actually double that for small jobs where I use only one torch and a bit more when I use two torches.

Setting up the forge and the time it takes to heat up is still a bit of a PITA so I do use a MAPP torch for lots of small stuff especially when it is often not possible to get things into a forge.

onanonanon
29th Apr 2018, 12:22 PM
Is it possible to fusion weld steel with a Mapp?

joez
29th Apr 2018, 12:34 PM
Has anyone tried Oxy/Petrol?


https://www.youtube.com/watch?v=hjp9kNWgrl4

https://www.ebay.com.au/itm/EnergyTech-PROCUT-Oxy-Petrol-Heating-Set-Alternative-to-Oxy-Acetylene-Propane/162295946669?hash=item25c9979dad:g:Q~wAAOSwjVVVwbRe




(https://www.ebay.com.au/itm/EnergyTech-PROCUT-Oxy-Petrol-Heating-Set-Alternative-to-Oxy-Acetylene-Propane/162295946669?hash=item25c9979dad:g:Q~wAAOSwjVVVwbRe)

BobL
29th Apr 2018, 01:32 PM
Is it possible to fusion weld steel with a Mapp?

There's Real Mapp, and Mapp replacement. See https://en.wikipedia.org/wiki/MAPP_gas

Real Mapp is a picture of propyne and propadiene and burns at around 2950ºC and has not be made available for about 10 years.
Mapp replacement is a mostly propylene and some propane and that is what you get in a Mapp canister these days, it burns at somewhere between 1950 and 2020 ºC depending on the mix.

I did not try all that hard but found I could melt the edges of small pieces of steel using real Mapp gas but not with the replacement. Although the combustion temps for both are well above melting point of steel its also a question of getting the energy into the steel over a narrow distribution area and the Mapp flames shapes are not really designed for pinpoint heating.

The welds produced by Mapp gas are supposedly brittle due to the high levels of H in the gas but on small welds the H can escape so it's less of a problem.