soldering after epoxy bolster

M

Mooreblades

Joined
Nov 28, 2013
Messages
29
I haven't been able to find any answers about tinning solder. Can you help me with this answer ...
After I epoxy my bolsters on, there will be a micro gap around the edges of the bolsters. Can this be filled
in with solder? The epoxy is rated to 180 F but solder must be heated much higher. Are there any tricks or methods
to making the bolsters flush with the blade? I have tried to make the blade and bolster perfectly square but to no avail.
Limited tools - 1x30 grinder, 4x36 grinder, 6" buffer, multiple hand tools
Any other ideas, with these tools above, to square up blade and bolders so no gaps?
Thank you for all you help and ideas.
Links and/or videos appreciated
 
No, you can't fill the gaps with solder. Solder and epoxy don't mix.
You can grind a concave on the back of your bolsters and flatten the edges with a file.
 
if you want to solder your bolsters don't bother with the epoxy. I fact don't use epoxy on any kind of metalic bolster. Either solder or pin them in place or both. if your tang and bolster are both flat there won't be a gap. here is the way I solder bolsters.

both bolsters and tang should be flat enough that when held togehter no light is visible between tang and bolsters. my method uses a piece of copper about 3 inches wide and five inches long. clamp 3/4s inch of one end flat in a vice so that you can place the bolsters on the other end not clamped in the vice. put the bolster on the copper with the inside surface facing up. spread some flux on each bolster, then put a piece of 1/16th dia. solder about 3/8ths inch long on each bolster. not heat the underside of the copper plate directly under the bolsters with a propane torch until the solder just melts if the flux turns black then stop cool things off and start over. push the mplten solder around on the bolster until the bolster is evenly coated/tinned. let them cool. now use your bruce bump stainless file guide to line your bolsters up evenly on the tang. remove the bolsters put flux on the tang and replace the bolsters. clamp the bolsters in place with a small pair of c clamp vice grips. the ones with the swivel pads work best. remove the file guide. now heat the tang bolster area from the tang side only. switch side to side to keep the heat even. heat until the flux bubbles and the solder melts and your done.
 
Solder and epoxy simply do not mix.

Mr. DeShivs and Mr. Burke are both highly respected. I will defer to them in these matters.

I'm of the school of thought that believes every joint should include mechanical fasteners of some sort, and when everything fits right and tight, there will be very little need for either solder or epoxy.
 
Thank you sooo much Mr Burke !!!!! This is one of the ways I read about but not confident with the source. This is the way I will go !!!
I know that this statement might sound bad to the pros here, but I have yet to get the tang and the bolsters perfectly flat with the equipment I have.
Hand sanding or even on my belt sander seems to leave a rounded edge on both. Any further suggestions on this ??
 
Do you use a true flat surface to hand sand the pieces on? A piece of granite from a cabinet shop or even a piece of glass will work well. Use masking tape to hold the sheet in place and start with 120 after your machine work. Frank
 
The info given is spot on.

A few additions:
The biggest reason people get gaps between the blade and guard is they fit the guard before the final assembly. The rush to "see the guard and handle in place" is a fatal flaw. The blade will get sanded after HT. This will make a guard fitted earlier sloppy, with gaps showing. The final fitting of the guard should be done just before it is installed.

Bolsters can be the slip-on type similar to a guard, or put on in two pieces. The two-piece bolsters should be pinned in place first and then soldered. All mating surfaces need to be dead flat for the two-piece bolster construction. Over-hammering of the pins can make the metal move and shop gaps that were not tere before. Pins only need the necessary amount of hammering to flare the ends.

All joints like bolsters or guards should be sealed in some fashion if the knife will be used. Capillary action will allow moisture to get between even the tightest joint. In kitchen use, bacteria can live there, too.
Some use JB weld applied during the assembly, but I prefer to solder the joint once all is fitted. With good technique and cleanliness, a solder joint is easy and a perfect shiny silvery seal. It is also permanent if done right.
 
Bill Burke said:
if you want to solder your bolsters don't bother with the epoxy. I fact don't use epoxy on any kind of metalic bolster. Either solder or pin them in place or both. if your tang and bolster are both flat there won't be a gap. here is the way I solder bolsters.

both bolsters and tang should be flat enough that when held togehter no light is visible between tang and bolsters. my method uses a piece of copper about 3 inches wide and five inches long. clamp 3/4s inch of one end flat in a vice so that you can place the bolsters on the other end not clamped in the vice. put the bolster on the copper with the inside surface facing up. spread some flux on each bolster, then put a piece of 1/16th dia. solder about 3/8ths inch long on each bolster. not heat the underside of the copper plate directly under the bolsters with a propane torch until the solder just melts if the flux turns black then stop cool things off and start over. push the mplten solder around on the bolster until the bolster is evenly coated/tinned. let them cool. now use your bruce bump stainless file guide to line your bolsters up evenly on the tang. remove the bolsters put flux on the tang and replace the bolsters. clamp the bolsters in place with a small pair of c clamp vice grips. the ones with the swivel pads work best. remove the file guide. now heat the tang bolster area from the tang side only. switch side to side to keep the heat even. heat until the flux bubbles and the solder melts and your done.
Click to expand...

I love what your saying brother but could you post some pics ?
 
Frank Niro said:
Do you use a true flat surface to hand sand the pieces on? A piece of granite from a cabinet shop or even a piece of glass will work well. Use masking tape to hold the sheet in place and start with 120 after your machine work. Frank
Click to expand...

Thank you Frank. I thought I was until I went out and put a long square across the table top. NOT TOTALLY FLAT. Luckly, my wife works at a custom kitchen cabinet house and have ask her to
bring my home a couple of her samples to use on my table top. Genius !!

bladsmth, again Thank you !!! You are very insightful on the rush. All my other knifes that I have made I have pinned and epoxied. I mostly make chef knives since I'm in the business. I hope to
learn more about soldering bolsters. Do you know of any tutorials or videos showing soldering of bolsters? I have seen many with guards but zero with bolsters.

Mr. Burke ... I will be attempting your recipe this week. I am hoping to finish this project soon. If I don't ruin it, being a rookie, I will post my final picture.

Thanks again to everyone and all insight and wisdom appreciated !!!!
 
This is a pair of Damascus chef knives I just finished. (6.5" & 7.25") I learned how to do the acid bath from videos, bolsters pinned and epoxied (David Boye), and handle made from
purple heart. (shaping handle videos off of youtube). I am on a mission to get all the wisdom I can from all sources. If you have more recommendations to better my skills,
I accept all constructive criticisms graciously.
lc10.jpg
[/URL] Uploaded with ImageShack.us[/IMG]
 
bladsmth said:
The info given is spot on.

The two-piece bolsters should be pinned in place first and then soldered. All mating surfaces need to be dead flat for the two-piece bolster construction. Over-hammering of the pins can make the metal move and show gaps that were not there before.
Click to expand...

capillary action work great when both tang and bolsters are carbon steel or carbon damascus but I have found that it is not reliable when stainless is added in there somewhere and pretty much don't work when the bolsters and tang are both stainless. By tinning the bolsters first then fluxind and clamping like I outlined before the solder joint is more reliable. the soldered bolsters can then be drilled and pinned. bolster that are not securley soldered will pop loose as you start to drill through the bolster into the blade. not to worry just remove the bolster from the bit finish drilling the tang bolster reflux clamp and reheat to solder.

I have some bolsters to put on tomorrow and I'll try to get pictures.
 
I used to solder my bolsters on but now I sand my bolsters on a disc sander with 320 grit paper. You can sand on a piece of marble too. I also flatten my blades against a flat platen on my 2x72 inch grinder and I go up to at least 600 grit but sometimes to 1300 grit before a quick buff. I also have been using larger pins and I slam them into chamfered holes of 5/32 with a 2 pound ball peen hammer. That alone smashes the bolsters into the blade. they fit so tight that the space between them appears to have vanished and thus no solder is required. Some of you will say that water could get under the bolsters and you might be right but it would be very little water and I only grind stainless steels now. If you are paranoid about this then by all means put some epoxy on them before peening the pins into place but I do think it necessary. If the two surfaces are as flat and smooth as glass then the gap would be microscopic. Just my opinion. Larry Lehman
 
I'm a big fan of solder simply cause I started making knives when most knives were
soldered. Don't believe you will ever hear anything bad about a good solder job.
Is it necessary? This pic is of a pair of brass bolsters put on by a 15 year old apprentice
of mine last week. He works with me 2 hours a day twice a week. You'd be damn lucky
to even get super glue into that joint.-no solder.
Ken.
 
You must log in or register to reply here.
Back
Top