Help with a solder choice for brass Chape

[Aaron Gouge 22]

Hey all,

      So over the past year I have been working a scottish dirk. It has been one of those back burner projects. I am close to finally having the drink done and am looking forward to starting the scabbard. So  I have pretty much no soldering experience! :-) Looking for some help. I have read many tutorials on this site related on soldering as we'll as watched many videos. Now I need some practice. But I have a couple questions.

       1- What solder to use? I know many like Stay-Brite

        2- Is silver solder adequate for a chape and throat or do i need to silver  braze them? Somethings like the SSF-6?

      3- Any tips on brass thickness or other tips on scabbard fittings? FYI my plan is to make the chape out of two pieces and solder the seams together, so a piece for the front and the back of the scabbard and solderd along the edges. 

      Thank you 

Aaron 

[Alan Longmire 3,678]

First, be very careful using the term "silver solder."  That refers specifically to the high-melting hard solders used by jewelers, the softest of which flows at about twice the temperature of silver-bearing plumbing solder.  Stay-brite is a soft silver-bearing solder, it is not a silver solder.  It has around 2% silver, 96% tin, and 2% antimony. It is fine for large areas like guards, or the bolsters on pocketknife liners, but it may be a little too soft for the chape.  It will break if bent.  

 

I had to look up SSF-6, and it's pretty much what I use on tomahawk bowls (I use Harris Safety-Silv 56).  Both are a 56% silver brazing rod, but the Safety-Silv is much smaller diameter than the SSF-6 I see on Amazon.  It will not break.  In fact, it will outlast the brass.  It has a slight brassy color, and matches well when fresh, but when the brass eventually tarnishes the braze line will stand out like a sore thumb.  So will the Stay-Brite, actually.  Which leads me to...

 

Sil-Fos.  This is a rod that is mostly copper, with from 5 to 15% silver and a good hit of phosphorus.  It flows at temperatures in between soft solder and hard solder/brazing rod.  It's mostly used by air conditioning and refrigeration companies, because it needs no flux (although flux never hurts), flows well, and fills gaps better than other alloys.  It will also color match the brass better than the others because of the copper content.  https://www.amazon.com/MILHAUPT-SIL-FOS-Silver-Solder-Sticks/dp/B016C2ONKC/ref=pd_cp_328_2/135-4027940-4541910?_encoding=UTF8&pd_rd_i=B016C2ONKC&pd_rd_r=c50b1dae-8634-4c97-9f3d-87c15337ce51&pd_rd_w=O8Hp6&pd_rd_wg=gWgun&pf_rd_p=e44de6bb-cc27-4696-9c22-3a1bddefabbd&pf_rd_r=XWAQQ30CG3Z3NPCPQM6E&psc=1&refRID=XWAQQ30CG3Z3NPCPQM6E

I'd go with Sil-Fos for brass fittings, because the ones I've done with any true silver solder tend to show the joints after a while.

 

Thickness:  This is a personal thing, but I tend to use 0.025" / 22 gauge / 0.65mm, but you can go thicker if you want.  I wouldn't go any thinner.  

 

 

[Aaron Gouge 22]

Thank you Alan! This is very helpful! The Sil-Fos will have enough strength in this application?  Would you say that on small sheet pieces for a chape I can use a Brenzsomatic TS8000  with the Sil-Fos? The TS8000 is listed for brazing and is said to have a output of 3500F, if I have correctly understood.  It would seem more than adequate?  

     Thank again 

Aaron 

[Alan Longmire 3,678]

Yes, on small things like that your torch is more than enough. And Sil-Fos is almost as strong as the 56% silver stuff.

[Aaron Gouge 22]

Here is a soldering question related to the scabbard throat. So if I make a cylinder of brass from flat stock it will have a vertical seam. It also will need a cap soldered on. My understanding is I can’t do this in 2 soldering heats because I will melt the solder out of the first seam while doing the second. So if I set my pieces up like the pic ( except my pic showed up sideways, so it should be the cylinder setting vertically on the cap) can I weld all seams in one go?  Can I flow solder/braze into the vertical seam without it just draining down onto the cap plate? 

[Alan Longmire 3,678]

If you were using soft solder that would be a problem. With brazing it's a bit different. Do the tube seam first with it horizontal, then do the cap vertically, heating from below.   With brazing you get a new alloy in the joint that has a slightly higher flow temperature than the rod alone, allowing you to do adjacent joints without melting the first one. 

You just have to be careful with the torch flame. 

[Aaron Gouge 22]

Thanks again Alan! I appreciate it. Just to clarify I can just use the one type of brazing rod(Sil-Fos)? My folks are coming down in about a month for a visit so I am working on a list of things we cannot find here in Ecuador for my dad to pick up for me! I’ll try and post some pics when I’m done. I might be back with more questions depending on how it goes :-) 

[Alan Longmire 3,678]

That is correct.  

[Al Massey 75]

I've had good results with Easy-45 solder, I think it melts about 1150 so not as bad as brazing but a lot stronger than the soft solder.

[Aaron Gouge 22]

So I know it’s been a couple of months but life has been crazy!!  So I went with the Sil Fos and it has worked great!! Finally have the Dirk and scabbard all finished up!! Thank you for all your advice!! 
  Aaron 

[Alan Longmire 3,678]

WooHoo!  Looks great!

[Aaron Gouge 22]

Thanks Allan! It’s been a very tedious build. Largest and most complex I’ve done up to date. A lot of firsts on this one. I am pleased with it.