I'm not one to shy away from something new but need a little advice on brazing. I made my first attempt ever here on my new lower firewall. I'm using a hand-held bottle of MAPP plus gas and a fluxed brass rod. After some time, I can heat the metal to just about "cherry red" and can just get the rod to melt but once it hits the firewall, it won't [re]melt. Do I need a hotter flame source? Or, should I make sure the rod end is melting down before touching it into the joint?

This is FUGLY!
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small tip oxy/acy

hotter flame I would think
I haven't brazed in about 15 years so a little rusty myself.
but an oxy/acetylene torch is the preferred way.
more heat that can be adjusted down to the correct temp
the base needs to be heated also with the torch to help it flow and avoid the instant cooling that you have.

And reasonably clean surfaces always help.

All good! Thanks guys. I'm looking around for a new or used gas welder.

Real MAPP gas went out of production around 2007/2008.

Replacement MAPP-pro gas isn't much hotter than propane.

MAPP-pro isnt going to get er’ done. You need more heat. Oxy-acetylene is the right tool to braze with.

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You need O2 to get it hot enough. I use one of these Benzomatic kits. You go thru a lot of 02 at $16 a tank.... but you can get almost anything red hot...
You can find it at farm and fleet or order from Amazon.

https://www.bernzomatic.com/Products/Hand-T...nition/WK5500OX

@Superhawk996 @Ishley

Great info. I just ordered the Benzomatic kit from Ace Hardware. This will hopefully help me finish the firewall on my "backyard LE project". FWIW, my father want's me to have his Gas Welder but he lives in CO. It might be a while before I can pick it up. I'm hoping this kit can do the job until then. Thank you everyone for your input. Y'all are the best!

One of those little Bernzomatic torches is where I started decades ago on my 1st 914.

Used it to fill the sail trim holes.

It will go through O2 fast. Gets expensive quick but will get er’ done.

A real Oxy-acetylene rig isn’t terribly expensive for hoses and regulators. The bottles are a one time cost (but can be double or triple hoses/torch/regulators). Build your own cart as project.

Master gas welding and you’ll find it easier to master other types.

Oxy-acetylene can also weld aluminum (with flux and special lenses to see properly).

Get a gas welding rig as soon as you can.

@Superhawk996 My Dad was always gas welding VW bodies into dune buggies when I was little. He taught me how to cut but I don't remember really getting a lot of time with the brazing rod. He's 86 now so he has no business welding any more. I'll pull an inventory of what he has next time I'm up there. His welder is probably from the 60s. Vintage!

Gas welding with Oxy/Acty is fun once you get the hang of it. I bet your dad was a cracker jack. Like anything else, takes a bit of time and patience.

Yes! My dad was a big motorhead back in the 50's. He and his hot-rod buddy used to modify old cars and street race them. BTW, he told me his buddy's nickname was "Jeg". My dad became an engineer and his buddy went on to create a high performance auto parts company.

Ya, Junior High School welding class...1975...sorry im old..

How cool!

You can always go a little cheaper and go oxy/propane will a grill bottle. Works near just as well for a lot less cost. Farm kid trick.

Good idea! Well, my Oxy/MAPP torch just showed today (cost approx. $60). Hoping to have enough O2 to do the job on the lower firewall tubes. I think I'll use my other MAPP gas to heat everything up and then do the brazing with this torch. Looking forward to this weekend.

I have all the oxy acetylene hardware, but used a simple MAAP gas hardware store torche. Really clean rust free steel is important. What really made things easier was using rod that is 57% silver. Flows so sweet. Get the ones coated with bright orange flux. Will try to get a photo later.
If you use a more powerful torch, remember that you need to have enough heat, but if you get the metal too hot it won’t flow either.