First Question: Soldering?

Archive ... When asked by members ...

As I'm working on an article on soldering for KI, I won't go into a lot of deatail, but Eutecrod 157 is one key ingredient, as well as their 682 flux. 157 flux may be ok, never used it, since 1971-ish, since I've been happy with 682. Now Staybrite must work ok, too, since many makers use it. Temp control is a major factor, watch the flux for temp. indications and of course cleanliness is important. I'd say that temp. is the biggest cause of success and failure, too hot and you have problems. OK for now? As I said, I'm new at this. I answered once and lost it after I previeved it, so this won't be previewed, what yo see, mispellings and all, is what you get! Hope this is some some help. Drop a line if yo have nay specific q's. I think, also, that PRACTICE is essential. One day, early on, I spen 8 hrs. soldering TWO guards before they were "right."

Thanks, SR

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Tom Mayo (07-14-2000 01:35 a.m.):actually....after 18 years...i finally figured out how to solder..what I want to know is how you get it finished like that....with the perfect radius etc.....do you put on a lot and use a tool to remove any excess??? how do you avoid getting flux etch on the ricasso??? how do you get such a nice finish on the solder when youre done... I want to know the REAL inside scoop here!!!
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I apologize, Tom. I use what is called a "Bright Boy" disc on my Moto-tool that's been sharpened, running the disc on a piece of 100x wet/dry, to smooth out the solder fillet (sp). Then I tape of f the blade and use a sharp edged buffing wheel to get into the corner and polish it. Then I remove the tape and hit the blade, as little as possible, including the flux etch, and clean it up. Over buffing will pit & groove the blade.The flux etch just happens, I personally can't avoid it, but one can minimize it, as noted in my previous treatise, by watching, very carefully, the temperature and using as little flux as possible. "Course you know that already, having made knives for 18 yrs.Advise if I can offer any more comment.Last night I remembered that the last time I tried to buy "Bright Boy" discs, I couldn't find them. Cratex has bought them out and they don't make that exact item anymore, so I called the factory, got some samples, and it appears that their disc model number 80-P works well. It is a little finer than the old one I used to use, but works fine. It will cut the solder, but not scratch the blade, but watch the guard material.They said that they could re-make some of the old "Finetex 382" but I'd need to get a few billion, or something like that. You might be able to find some fo the old ones. I got mine, initially, from James Poplin, a supplier in Washington GA. Not able to contact him today, got a recording, "...no such number." If anyone can find any of the Finetex 382, save me 20 or 30, OK?
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S.R. "Steve" Johnson
www.srjknives.com

Archive ... cntd.

I still round my ricassos, but because I like the looks of them, but they might be a LITTLE easier to get the solder to flow, I agree.I cut a slot into my tangs for the guard to slide into. Be sure to round the corners, though.My guess would be that things are getting too hot, and maybe you're spending too much time with the high temp. That's just a guess. Get the solder on as soon as the flux "melts" and get it brushed into place with a little flux. Wipe the excess off with a Q-tip before it sets up.If I could only come to HI I'm sue that we could figure this out in your shop.

SRJ

Steve: Have used the 157 Solder, but would like to try the 682 flux. Can you please provide a source?
Also, I've had great success usine a piece of 1/8" nickel silver rod, beveled back about 45 degrees and mounted in a file handle to "shave" off the excess solder. This tool both cuts and burnishes, and won't scratch SS guards/bolsters or the blade. Cleanup on the buffer is a snap.

RJ Martin

First of all, how did the 157 flux work, or did you use that?

You can contact Eutectic USA @ 704 527 9800
They should be able to give you the name of a local supplier.

Their web site is: www.eutectic.com/
Email their welding product information rep @ AOsborn@eutectic-na.com

My tech. rep. says that 682 flux is available, as does the technical and customer service center at the number above.

The only problem is: They must ship it as a hazardous material, so there will be an added cost for shipping, and they ship them in a pack of three jars, 8 oz. each, for $67.30, plus a haz-mat charge of about $30-40 that the distributor tacks on. Therefore, one jar could run you $35 or so, if you can get one jar. The guy there agreed that 682 would be the flux to use for SS soldering.

They are presently trying to come up with a way to ship single jars.

Call them and see what they can do. Let us know how it goes, please.

Steve

I have used Eutectic 1800PA for years. After 30 years of knife makeing and guard soldering I'm only on my second tub of Eutectic paste solder. Like everyone else it took what I considered forever to learn to do a good solder job. Knifemaker Michael Collins is the one who put me on to Eutectic paste solder many years ago. As far as I know he still uses Eutectic paste. As you are aware, the blade and guard have to be CLEAN.....Real Clean. I rough the area behind the guard with a Cratex abrasive wheel....even the cut out where the guard slips up and onto the blade. I do my own heat treating so I get some de-carb, so I have to pay particular attention to the de-carb formations on the blade.....roughing these areas up will normally do the trick.I make sure the guard is a real good fit. I apply the paste to the inside of the guard and slide it onto the blade. If the guard is a tight fit the solder is forced out of the front and back of the guard showing me the fit is good and I am now ready to apply the heat. One trick I learned some time back is to take a soft lead pencil and scribe a line about a 3/32" above the area infront of the guard on the choil. This graphite pencil line keeps the solder from over flowing onto the choil and also aids in the removal of the fulx. I have found that the Eutectic 1800PA flux in non-staining and is very easy to remove. I use very little solder on the joints....a little goes along way. Clean-up is simple I use the same method as you....sharp Cratex wheel and then polish with a knife edge felt wheel. Patience is the key to soldering a guard....I don't have to tell you, but to others having soldering problems..... it's important not to push your heat....slow heating goes along way.
Keep up these great topics...I'm still learning.
Jim

Thanks, Jim. My only problem with paste solder has been some bubbling, sometimes. I don't have that problem with the wire...and don't know why, either.

Good advice, also, on the heat. Slow is good. That's possibly why the heat gun works so well for me.

I have used the 157 solder and liquid flux, as well as Allstate Paste solder. I prefer a more viscous flux, rather than a thin liquid. While I am able to produce a nice looking fillet, I don't feel I am getting complete penetration into the joint. The "wet out" isn't too good. As I pin all my slotted guards, a lack of penetration is not a big issue, but, I get occasionally some discoloration over time due to trapped flux, which usually appears at the top of the guard-very annoying!!!!!!!!!!!!

I've experimented with a variety of surface preparation techniques, and clean up woth Acetone before soldering, but still have troubles.

Ideally, I'd like a wire solder with a flux that has the consistency of motor oil and will stay put as the heat is applied.

RJ Martin

Here's a big long commentary on soldering from page two, should you like to have a look:

pub42.ezboard.com/fcustom...D=10.topic

The first time I went to Edmund Davidsons house a couple of years ago there was an awful smell coming from the kitchen. He was boiling a turtle in one pot and several blades in another. I have been boiling my blades with soldered guards in baking soda and water every since. I leave them in for several hours. It seems to get all of the residual flux out of the joint. I use the paste flux inside the guard and add flux and solder to the joint when the heat gun gets every thing hot. Stroke the molten solder with a rod dipped in flux and burnish with a brass rod like RJ described.
Regards,
Mike Snody

Now why doesn't a boiled turtle in Edmund's kitchen surprise me? The boiling thing works, see link above. I only boil for about 5 min. but it really helps, I add a little dish soap.

Thanks for the tips.

Dont know how I missed the link. Great information.
Next time you see Edmund ask him to tell you about the seven kinds of meat in a turtle. Make sure you have a few hours!
Regards,
Mike Snody

Guys: I have done the baking soda trick. But, if there is trapped flux, then, there IS NO SOLDER in the joint. That just doesn't cut it for me!
But, after reading the link, my suspicion is that I have been overheating the joint. I'm gonna get me some of that 682 flux and have another go, with my heat gun this time instead of a torch.
I'll keep you posted. THANKS

RJ Martin

Gentlemen
I've been boiling turtle and knives together for years...Rade Hawkins swears by it. The baking soda breaks down the cologen in the shell and a filmy oil floats to the surface. Not only does this oil stop the action of the left over flux oozing from freshly solder guards I use it to coat wooden knife handles...keeps them from shrinking. (WARNING).....Do not rub this turtle oil slime on Osick....If you do wear eye protection. A little bit of this stuff goes a long way.

Jim

Hey,

Don't forget to tell RJ if you add a little possum to the knife/turtle mixture in the pot it doubles the strength of the resulting residual oil which subsequently penetrates the incompletely soldered guard joint, redistributes the solder evenly, and smooths the guard/blade joint so no burnishing is neccessary !

Lets not leave out any important "secrets" here.

Schuyler