How to Choose and Use a Blowtorch | Ask This Old House

Ask This Old House heating and plumbing expert Richard Trethewey explains how to get the most out of each type of blowtorch. (See below for a shopping list, tools, and steps.)

Shopping List for How to Choose and Use a Blowtorch:
- Solder
- Flux
- Emery cloth
- Brush
- Flint (if needed)

Tools for How to Choose and Use a Blowtorch:
- Propane-fueled torch
- MAPP-gas-fueled torch

Steps for How to Choose and Use a Blowtorch:
1. Richard says your choice of blowtorch depends on the type of job you are doing.
2. For smaller jobs involving _-inch copper pipe, it’s best to use a pencil-tipped propane-fueled torch.
3. For larger jobs involving copper pipe _ inch or more, it’s best to use a hotter flame from the MAPP-gas-fueled torch.
4. To make a copper-pipe connection: Clean the outside of the pipe and the inside of the fitting with an emery cloth.
5. Apply flux to the pipes and make the connection.
6. Apply the tip of the flame to the flux connection.
7. Once the flux begins to melt and drip, place solder on the opposite side away from the flame.
8. The flame will draw the solder all the way around.
9. Once the solder is drawn around, remove the flame from the pipe and let the connection cool.

About Ask This Old House TV:
Homeowners have a virtual truckload of questions for us on smaller projects, and we're ready to answer. Ask This Old House solves the steady stream of home improvement problems faced by our viewers—and we make house calls! Ask This Old House features some familiar faces from This Old House, including Kevin O'Connor, general contractor Tom Silva, plumbing and heating expert Richard Trethewey, and landscape contractor Roger Cook.

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How to Choose and Use a Blowtorch | Ask This Old House

[lkylky]

This guy's review is way much better and easier to understand than the junk video that Benzomatic posted on their website. Thanks a lot "This Old House".

[kevinfetner]

I've been a plumber since '78 and some things don't change....like how to properly sweat a joint. You only need to flux the pipe, not the fitting too. Of course everything is cleaned first with either brushes; internal/external or sandcloth...or both depending on the size of the joint. A good plumbing torch will let you adjust down to smaller jobs like 1/2-3/4" and also sweat larger sizes. Some of the small bottle 'turbo' torches won't do turn them down and the tips excessively heat to cherry red...not a good scenario. Better to have smaller tips that exchanges in & out for the smaller pipe sizes. I've had portable propane and MAP torches that work from 1/2" to 1/1/2". Honestly though unless I have access problems, anything over 1" and I'm using a bigger acetylene bottle and Turbo torches with different tips. And my fall back standard would always be my old Prest-O-Lite on acetylene. I've been on jobs where the plumber is struggling (time-wise) with a little bottle torch like under a house. Fire up the Turbo on a acetylene bottle or the Prest-O-Lite and cut the job time in half. The little hand held torches are for tight space and convenience, not for whole house sweating. The nice thing about the larger tanks torches is they have regulators and so you can fine tune your torch flame for the job at hand. I worked for a company once that forced everyone to use the small bottle torches for everything. That is, until I showed them how much time you can save on a whole house job using acetylene. But then I got stuck training the guy on how to use a large torch bottle set up. On most residential piping now it's all PEX style piping anyway. You can't win...glad I'm retiring...lol. Sweating will always have its place for repairs though and of course, HVAC.

[kolochodelrio]

Rich has Always been the best of the team

[TheSlipperyNoodle]

Worth noting that, in most of these videos, Richard uses a Bernzomatic TS4000 with propane.

[MrWhitelightning]

Appreciate the wisdom and experience these guys provide ❤️

[danielmecom]

Great info for someone that is learning slowley to do plumbing and wants to make a forge as a hobby. Thanks for the knowladge. Mush help full

[giulioluzzardi]

Melting point of new "Lead-free" solder is higher so we need more heat, thanks for the tip, I knew it was taking too long to flow.

[WARTHOGU]

The original MAPP gas production came to an end in 2008 as the sole plant making it discontinued the production. ... In early 2008, true MAPP gas production ended in North America when production was discontinued at the only remaining plant in North America that still manufactured it.

[thirtyfourthnvine]

Everyone in the comments section knows best. I’ve been plumbing for ever and here’s what I’ve learned. ....
Ask 10 different plumbers the right way to do something and you’re sure to get 10 different answers. Best to learn from trial and error and stick to what works for you... having said that I prefer mapp gas each and every time. To me it just seems faster and more reliable

[shootacarlos]

I use the second blue torch for dabbing works perfectly fine

[chrisdick]

ive always used MAPP and Acetylene never used propane in all my years of doing plumbing work never had a problem with any if my fittings

[Binzdogger]

Fair enough. I watched this as I wanted to find out which torch to use, couldn't be any more to the point, learn a little soldering tip, good vid. Liked / Subscribed

[Quentyn]

For any work I HVAC pipes you need the yellow can. Pipes are thicker and solder is silver

[gibsonethirty]

Here's the thing, if you take that MAPP torch off the MAPP bottle and put it on to the Propane bottle it will do exactly the same type work that they say you need MAPP for. Its all a rip off. In my experiments, Propane with the TS8000 MAPP torch fitted heated up the work metal (mild steel flat bar) 12°C hotter than if I used the MAPP setup after 1 minuet of heating the metal both from a base temperature of 18°C - MAPP 415°C, Propane (same torch) 427°C. Make of it what you will. I Silver solder now with the MAPP torch on a hose connected to my 9Kg Propane bottle that I also use for camping (running the cooker on the camper trailer) so now I can take a means of doing road side repairs to metal work when outback if I need to, just one hose and the torch, easy to pack.

[borys]

Richard is a good plumber. Thank u for ur help.

[Falcoable]

Never gave the map gas torch a chance, you can turn it down! And too much flux and solder!😉

[frankmontez]

I've just heard old mapp gas no longer available ? Why did they discontinue this ? I really liked it.

[MohamedAli-eonb]

Great men with great experience. Thank you teaching us.

[TheAed]

It's always a safe practice to leave multiple propane torches on while you work.

[DragonBuilds]

The tiny little pencil torches are only really good for 1/2 and maybe 3/4 copper.