Brazing technique advice needed

[picclock]

I need to braze a 40mm steel disc to a piece of 15mm steel plate, with a 1mm deep location recess for the disc. For me this is a large piece to braze, and I have ordered a larger torch to ensure sufficient heat.

My real issue is how to feed the silver solder into the joint. For small work I normally make precut shapes (pallions ?) and when these melt capillary attraction wicks the silver solder into the joint and job done.

With a 40mm diameter flat surface I'm not sure that the solder will wick in enough to cover the surface. I'm wondering if I should place a solder ring under the disc, such that when the solder melts the disc will (hopefully) settle down into the correct position, with the solder evenly filling the joint.

What is the best approach with this type of joint ?

I also need to silver solder a piece on the other side of the plate after some machining operations, but as the disc will be held in place by then (by means other than silver soldering) I presume reheating the joint will not cause any issues.

Any advice or experiences most welcome.

Best Regards

picclock

 

[krv3000]

hi well the ring metherd will work but i have dun this in the past and it works well get a nice clean file and a sheet of paper i used a large peace of wall paper filed i have with the pattern side dawn IE so you is working on a clean base file sum silver solder on to the paper just guesstimate haw much you will need once you have dun that place the filings in a clean container then mix up the soldering flux then ad the silver solder filings to the flux and mix the two together then spred the mix on the job in hand hope this helps

 

[picclock]

@ krv3000

Thanks for that idea. I think I'll just flatten some silver solder pieces and put them underneath the disc. However, I can see a lot of uses for the method you outline as it allows the silver solder to be placed in very small gaps. Will get filing today.

Many thanks for the info.

Best Regards

picclock

 

[Jasonb]

They make silversolder foil for the same effect and you can also buy paste to save you having to file the rod.

J