Unable to solder stainless steel bolsters

JPSWorks

JPSWorks

Well-Known Member
(UPDATE SUCCESS!)..Unable to solder stainless steel bolsters

Hello everyone. I was hoping to get some soldering guidance from those with more knowledge and experience than I do.

I am working on a slipjoint and was attempting to solder on the bolsters because I don't currently have a spot welder. A while back I was able to successfully solder brass bolsters to brass liners. I had read and watched many tutorials that made it go much easier than I thought it would. Today was the complete opposite. The difference is that this is the first time I have tried to join stainless to stainless.

I used 410 ss for both the liner and bolster.
Sanded them completely flat by hand on sandpaper over thick glass.
Roughed the areas to be soldered together.
Used nitrile gloves and cleaned everything thoroughly with acetone.
Wiped it down and clean it again letting it air dry.
Applied the paste flux to all the each piece the laid a coil of solder on.

I attempted to tin each piece by heating it over the torch, moving it in and out of the flame. When it began to melt I tried to spread it around with a steel rod but it just wanted to pool in the center. Even using the rod I couldn't spread it out over the whole are. When I was tinning the brass each bit of solder would melt and flow evenly out to all sides. I could then use the rod to spread it around if I missed spot then knock the rest off. It left and nice thin shiny tinned layer on each piece. This just looked like a round blob in the middle, and a brownish barrier around the solder.

I am obviously burning the flux before the solder has time to melt even though I tried to heat it slowly. No matter what I tried it kept burning. For those that have done this many times, can you tell me what I am doing wrong? Am I applying too much flux, or am I even using the correct type of solder and flux for the job? The flux is this weird white cream that came with a brush to paste it on. Not liquid like I have seen in some how-tos.

Hopefully the pics below with show more what I am referring to. I appreciate any and all help with this.

Thanks again,

John




 
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Hi John

It sure looks like you are burning the flux. I never have liked the water soluble flux. Try some Stay Clean flux and I bet you have better results.
I am not sure what the silver content in that solder is. Maybe less than 1%? I use the 4% silver solder and have never had a problem with it and using the Stay Clean flux. I do a lot of soldering and brazing for my job.
http://usaknifemaker.com/catalogsearch/result/?cat=0&q=solder
Joe
 
I tried typical plumbing solder and flux found at most home type stores. I couldn't get it to work well with stainless with out a lot of effort. It will work if you get the hang of it.
I found Stay-brite solder and flux worked much easier, more often for me.

It does take a few practice runs to learn when the flux is ready and you have to kind of sneak up on heating the solder to liquid.
 
Thank you all for your help with this, and the links. I read the wip.

This afternoon I cleaned up the pieces and gave two of them one more try, heating them up very, very slowly. Keeping them above the flame and out of the direct flame. Still wouldn't stick and tin the pieces. I had to give up.

Looks like I will have to just jump online and purchase the stay bright flux and solder. I haven't seen it at the local hardware stores.

Thanks again.
 
Definitely wrong flux. You need a flux made for stainless steel. sta-brite solder and flux work well together.

Stan
 
I wanted to post an update and a thank you to all of you who helped me out with this issue. Wow what a difference using the correct solder and flux makes. I ended up finding a specialized hobby shop in town where people build and customize RC cars. They had Stay Brite solder and flux. First time I tried it I was able to tin successfully and I just finished attaching the bolsters. I learned from this and am thankful for the assistance. Another reason I love this place.

On a side note, I realized something else that you will probably notice in the pics. Next time I need to try to not make the bolsters so oversized but closer to the size of the actual liner. Lots to cut and grind off.

Thanks again everyone,

John



 
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