Brazed roof raise?

[TaliaDPerkins]

I don't have good confidence in my welding yet, but to use my spray foam before it's expire date I must use it soon. I have a lot of experience soldering.


I am thinking if I rivet and braze the hat channel extensions in and have several square inches of join at each end of the vertical members, I'm good.


Feedback on my feeling there is appreciated.

[ol trunt]

MY OPINION--NO! Braze isn't a weld--it's bubble gum!
Jack

[TaliaDPerkins]

Common steel brazing rod from Home Depot has 64kpsi tensile strength.


Common mild steel welding rod is around 70kpsi. This strikes me as not that much different, especially when I know I can flow the braze into a much larger area than a weld bead.


Anyone know of a brazed raised roof?

[magnakansas]

airplanes, and single seat racing cars made in places outside the of north america...

most were brazed --- take apart tube frame Lotus, BRM, Jaguar whole slew of them and you will find brazed frames.

A good braze weld will tear parent metal. If you are used to braze welding ... sure go for it. It is not seen that often here in the USA.

motorcycles, bicycles used to be brazed at one time...

Engineer it, don't just build it... but, yea brazing should be fine... Just a different way of doing it. not better, not worse, different.

william

[flattracker]

A suggestion:
Take a welding class at your local community college. Even an introduction to welding class will be very beneficial in the insight you will gain. You would get hands-on experience that will help you make your decision on how to proceed.
Brazing steel applies a lot of heat for a longer time than MIG (wire feed) welding. Some steels may end up with less strength from that.

I have also ended up with cracks in steel after brazing it.
Brazing has its places for fabrication, as well as welding.
I would not braze an roof raise though.

[fo4imtippin]

You can get ugly well penetrating welds in no time. I just started welding and while I haven't done anything my life depended on, I should have gotten a $200 flux core welder a long time ago. You will save money buying a flux core welder over brazing gas. Honestly, I think brazing looks harder.

[Jolly Roger bus 223]

i braze and weld for a living and have been doing it for over 20 years.
in my brazing experience (silver and steel) i think the brazing heats up so much more surface area to pull the brazing rod material in.
the welding is more specific penetration at that area and even though more heat it is at a specific area not heating the entire area to prep for the braze to pull in.
on thicker tubing yes i would think it is fine but on hat channel of (16-15 guage ) i would say no.
and why is because everything i have brazed that was below sch10 ended up being soft under decent pressure.
heck even with copper that i braze i will not let my men braze a male or female adapter because it softens the fitting to much and when you put a wrench on it whether backup or insert they egg shape and leak. even with the correct wrench.
i have brazed to many pieces of ladder racks back together from harbor freight but the difference is they have a sleeve(backing ring to braze to) because you put them together. but that makes it maybe 16guage tube brazed to schedule 20 insert.
good enough for a ladder rack but wouldnt haul any of my loads of piping with it.
personal opinion yes.
to much heat. to thin of metal. means one warpage while you are doing it and a whole lot more prep work to get that metal ready for brazing including flux as needed verses a cheap harbor freight welder and some test pieces in the position of your raise with the exact same material.
dont waste your time with the harbor freight wire.

[TaliaDPerkins]

I'm getting good advice, I think, in both directions.