Gap for brazing thin casting? Non-automotive

[Mattax]

Do I need some gap when brazing something this small?

I did this once before with a cracked flat register grill, and just tinned it. It flowed in like solder and was nearly invisible. But this broken clean through so the repair will need some strength.

Then there is this a register than needs to be done.
Any suggestions on how to approach it?

My thinking is it might be best to work from right to left, and attach the corner piece last.
Might have to heat the opposite side to equalize the expansion.

Of the rods I have, the Xuper 146XFC seems to be the most appropriate

https://www.castolin.com/sites/default/files/products/docs/Xuper-146-XFC.pdf

 

[67Dart273]

I don't think you need much of anything for gap, but it needs to be CLEAN. If you can, find something to reinforce the unseen side, if possible.

 

[mopar head]

What are you calling thin?

 

[Mattax]

.120"

 

[mopar head]

Yeah that`s pretty thin, I`d still put small bevels on each side about half way through clean good as said above and have at it.
The rod you have is great stuff.

 

[Mattax]

Small bevel helped.
The pieces were short enough that setting them upo tight there was no noticible opening of the gap. I tried to preheat on a hot plate and then with the torch.

What I found helpful was using the smallest diameter rod 3/32 of which there was just a partial one left. Not sure what the material is as its no longer listed in Eutectic's catalog. I'll have to contact them. Melting point is significantly lower than the 146.

Did not quite flow through all the way.

 

[Mattax]

I joined the 4 pieces as pairs and then together.
Then attached to the long side of the frame.
Did the corner last. Got creative on holding it together but it worked well.

The 1/8 rod provided more bead than needed but it will file off.

 

[67Dart273]

Part of the reason you didn't get flow through is likely because of the backup piece acting as a sink. For those kinds of work, may not be an easy solution. But does it actually need that to be strong enough?

 

[Mattax]

The back up piece was to keep it in alignment. I tried to keep it all on the hot plate before brazing. But 200 degrees is not really close to 1500 degrees.
I think it will be strong enough without anything else.

 

[Mattax]

Cleaned it up a bit and assembled with the new louver. It will be functional. Next will be making it look nice.
I think smaller diameter rod, better prep, and better control of the torch heat.

 

[mopar head]

It will be functional.

What is that used for?

 

[Mattax]

What is that used for?

It's the register for the front room in my house. It uses a gravity (warm air) heating system.
Some time between 1977 and 1993 the parlor mantel and the register were removed. It looks bland, and also most of the rest of the originao stuff is still in the house. Slowy very slowly at times, I've been restoring it.

The folks next door sold their house and the new people loved all the old stuff, and promptly gutted front part of the first floor.
Sad after three generations of the previous family living there since 1927 or so. I even have pictures from 20 years ago when they had the wallpaper stripped and the origina paperhanger's signitures were on the walls and the even in the palster crown molding.

Anyway. I saw the remains of their front mantel on the porch and they said take it if I want.

fast forward

The working part of th e register goes into a sheet metal box. A couple of tin straps fold over to keep it from falling out. Then the grill is held on with 4 screws.

When it gets alittle further along I'll post back. I made a major mistake this evening grinding some of the brick mortar in the duct opening. Dummy me didn't shut the vents and stuff some rags in the duct 'flue'. It came through every vent in the system. So basically all the rooms but the kitchen have fine dust layer. So guess what I'm doing next.

 

[Mattax]

Took a while to get all the patches in the wall and pieces test fitted.

When the paint is dry I'll put the working register in. and then the grill. But this is a test fit with a spare grill.

Still working on a copying the control rod threads for the register that allows heat to go up the flew. Need it for a similar second floor control.

Looks like 24 threads per inch but its a rounded thread form.

 

[Mattax]

The register has a patent cast in for 1872 which helped me figure out the manufacturer was Tuttle and Bailey, which was mostly unreadable in the casting.