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Pat
21st May 2010, 01:22 PM
<hr style="color: rgb(36, 49, 63); background-color: rgb(36, 49, 63);" size="1"> <!-- / icon and title --> <!-- message --> :ranton:I am trying to weld a new Band Saw blade together, using the jig from Carbatec. I got the ends ground to a taper, flux and the silver solder. I am using one of the "Little Devils" from Bunnies. My problem is that I cannot get the solder to melt fully. Is it because I am not generating enough heat - get a bigger better torch Mapp gas or equivalent?

At the moment I hate the little :toot: . I have followed the instructions to the letter and it doesn't work!

The blade is Starrett 1/2" 4 tpi. So I don't think it's the blade quality.:rantoff:

wheelinround
21st May 2010, 02:31 PM
Heat is important to little and solder wont flow or stick to much and blade melts solder runs off.
What % of silver in the solder is it Pat?? 60% is best.
the clamp could be absorbing some heat Pat the colder the day the colder the steel.

wheelinround
21st May 2010, 03:13 PM
Learn stuff (http://www.merseyturners.co.uk/learn_stuff2.htm)

issatree
21st May 2010, 04:27 PM
Hi Pat,
I do my own Blades, but I use 3/8" x 6TPI. I find the 4TPI. to dangerous for me to use as I only cut small stuff, mainly round.
I bought 100 ft. for $81.50, from McDivens Saws in Williamstown, Vic.
Therefore my Blades cost me approx. $7.55 ea. I get 12 Blades from the roll.

I take it when you say Solder, you mean Silver Solder ?.

I was lucky enough to buy some 16 sticks 12" long of Low Heat Silver Solder for $1, at the Castlemaine Swap a few years ago now, & it works a treat.
I hardly ever Break a Blade, they just wear out.

I was also in the right place to buy at Auction a " Yanes w/- Advanced Piezo Blow Torch ". Cost $5.50. Brand New.
I chased another 1 recently, went to $17, & I passed.
It is made in Brasil. It has COD.4450 on it, & I take that to be a Code No.
The Cartridge cost is $3.50, & lasts forever. Has amazing heat, & does those Blades easily.

If you wish I can PM you on how I do it, & if I can do it, anybody can, as I'm almost self taught. I was shown a little on the mistakes I made, but that was all.
Regards,
issatree.



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kayu
21st May 2010, 04:56 PM
Hi Issatree,

Me and I'm sure others to would like to know how you braze your blades.
Why don't you show and explain it here?

Thanks in advance,

John

orificiam
21st May 2010, 08:33 PM
What He :aro-u: Said.
Cheers Tony.:)

John Lucas
22nd May 2010, 01:03 AM
You need more heat and you did you mention flux? I may have read it too fast. I use a MAPP gas torch for silver soldering. The solder will flow where it's hottest and you have to get it fairly even to get it to flow to all the areas of the joint. This takes a fairly broad flame and/or more volume. I've done really small things with propane but for anything with any size or thickness it takes my MAPP gas torch.
If the metal is dirty it won't solder or won't solder evenly. Clean it first. Usually just the grinding or sanding will work but if I let it sit too long I clean it with Naptha.
I'm not an expert on this. Only done it a few times but it's a pretty simple process. I have done a fair amount of silver solder while trying to learn jewelry making so I'm starting to get a handle on that end.
I don't have photos of the process but there are jigs sold on the market to help you keep the blade parts aligned. Grind down the blades so they overlap in a Scarf joint kind of way. Apply flux to the joint and if you have ribbon solder put that in there. Then just heat it up until the solder flows to all parts of the joint.

hughie
22nd May 2010, 10:06 AM
One of the secrets to silver soldering is also neat joints. Silver solder has a great capillary action and is strongest with fine capillary type joints. So pay strict attention to making the scarf as neat as you can.

The higher the silver content the more forgiving it will be and less temp is required. But the down side is more silver, less strength and higher cost.

Its a balance between getting a strong joint and ease of use. Check with your local welding supplier as to what is recommended for joining band saw blades and go with that.

As John has mentioned keep it clean, as clean as possible. When cleaned do not even rub your finger across the joint area as this will effect the way the solder runs and sticks.

Heat, take your time, don't be in a hurry as it may not get up to the right temp and that will only add to the problems.

Flux is usually wet, do not allow it to dry out as its not resurrect-able and use sparingly. Just coat both sides of the joint with a thin covering,putting heaps on only makes the excess bubble out its hard to see whats going on.

How strong is silver solder? Well I have seen it tested to 2500lb per sq inch and pass with flying colours.

Once you have mastered it, it will be come second nature.

issatree
24th May 2010, 05:19 AM
Hi to all,
I had sent Pat a PM, but have now been asked to put the reply for all to read. This is most likely not the correct way of Brazing Blades, but is the way I do it, & it works for me.

I put about a 1mm. bevel on both ends of the Blade, & using my White Wheel. I then run the Blade Bevels lightly, over my Wire Wheel.

I put my jig to 1 side in my vice & keep it away from conbustable materials.
My friend made up my jig out of 25 x 25mm.angle iron with a hole cut out in the centre.
This jig has 4 small hex. bolts with 10mm washers, to put the Blade under.
He also milled out a section for the Blade to sit in under the washers, & to keep the back of the Blade straight.
I then secure the Blade with 1 Bevel over the other.

I take the Silver Solder, & belt it with a hammer so it is flat, & cut a small piece off about 1 1/2mm. & holding it with Needle Nose Pliers as it will fly. With another pair I lift 1 side of the Blade, & put the S/S between the Bevels. You also need some White Out Correction Stuff.
About 1/2mm.from the join, put 1 stroke of this on either side of the join.
Believe it or not, this stops the S/S from running away.

Apply some flux & not to much, put the flame to the Blade, & bingo it is done. It needs to be Red Hot so the S/S will run. Just before you remove the flame, squeeze the join with a pair of pliers. give it time to cool.

2 things, my S/S is Low Heat S/S, & my Blow Torch is Brasilian made with a Cartridge & a Peizio Starter.

After the Blade has cooled off, I use a 10in. - 250mm. round wood in the vice, to put the Blade over & file the excess off on either side, but be careful that you don't file to much, & file the back straight. I think 1 of the tricks is not to use to much S/S.

This works for me, & most of my Brazed Blades wear out & do not break. Yes,
sometimes they go bump, bump, but not as often now that I have the hang of it.
Also, I will do 3 - 4 Blades at 1 time, just makes it easier.

I may have stated earlier, that I buy Skip Tooth of 100ft. x 3/8in. x 6 teeth per inch, for $81.50, from McDivens Saws, In Kororiot Creek Road, Williamstown, Vic.

So my Blades cost me approx. $7.55 ea. & I get 12 blades from the roll.
Hoping this all makes sense, & if you need to know more, just ask.

Another small trick I learnt, was to take a bluntish blade, turn it inside out, so the teeth are facing up, when you put it back in the saw, & with a file at about 1 - 2 Deg. & sitting on the table, lightly file the teeth, while it is going. OK, so, yes the set is gone, but it will still cut for quite some time, & doesn't do a bad job.

Regards,
issatree.

hughie
24th May 2010, 09:31 AM
Good advice Issatree. :2tsup: A jig is well worth the effort of making for both grinding and soldering.
Richard Raffan re-cycles his blades by touching the up on the grinder. If you have a steady hand its worth a try.

oldiephred
24th May 2010, 09:50 AM
I us a ribbon type silver solder 1/4" wide x 1/32" thick. The flux is a paste type.
Procedure I use: Made my own jig but that is irelevant. Bevel the blade ends, install in jig, apply flux on beveled faces, cut a SMALL piece of solder and place it in the joint, heat with propane torch until cherry red and the solder flows well. (with a propane torch this will take 4 - 5 secs. max. IMMEDIATELY remove the heat and DO NOT try to "improve it" Re-heating the solder will ruin it.
Remove excess solder and make smooth on a drum sander or something like that.
Works well for me.
If you have not already done so, check on gas flame shapes and see where the hot point is for various flames, It is usually near the tip where the flame can often not be seen. This knowledge can effest your soldering quality.
Lotsa luck.

wheelinround
25th May 2010, 09:17 AM
Good advice Issatree. :2tsup: A jig is well worth the effort of making for both grinding and soldering.
Richard Raffan re-cycles his blades by touching the up on the grinder. If you have a steady hand its worth a try.

I have heard a story of Richard asking at a club demo for a sharpening stone when he found the BS blade to be dull when he got it turned the BS on and used the stone to touch up the blade. No he wasn't taking the back edge away

bowl-basher
25th May 2010, 10:47 AM
Just a comment from someone who has spent the last 25 years in the welding game..... make sure the silver brazing alloy (correct name) is a MIN of 45%
most commercial saw makers and repairers use a silver brazing alloy of 50% with 3% nickle to give the joint or tooth that extra toughness this should be avaiable from any decent welding house for you Victorians ther is a company in Thomas town Melbourne callled SBA Australia they make the stuff and will be able to tell you who stocks their product (no conection just one of my old suppliers)
Regards
Bowl-Basher

Big Shed
25th May 2010, 11:10 AM
I could be wrong but I thought most commercial bandsaw blades were resistance welded with a machine similar to this?

Band Saw Blade Welder - Grob Inc. (http://www.grobinc.com/bandsaw/blade-welder.htm)

Pat
25th May 2010, 06:15 PM
Nice Fred, but a little out side of the cheap price range at US$1800+:;

Big Shed
25th May 2010, 06:21 PM
Nice Fred, but a little out side of the cheap price range at US$1800+:;

Don't be a cheapskate Pat, that would look good in your new shed:2tsup:

But I was responding to this statement:




most commercial saw makers and repairers use a silver brazing alloy of 50% with 3% nickle to give the joint or tooth that extra toughness

.....................

Regards
Bowl-Basher

wheelinround
25th May 2010, 06:27 PM
I have to re-teach myself Silver soldering but having a friend who has access to a BS welding machine just makes me lazy. :U

Pat
25th May 2010, 07:02 PM
:gaah: I surrender!

Attempt 42564316465423132165431345643165464231 failed again. Solder flattened, edges scarfed, flux fluxed, jig and 100mm either way heated, join heated to cherry red, Allowed to cool naturally. Join failed to stay joined even while removing it from the jig!

:frustrated::club::fit::rant::upset::ranting2:

DJ’s Timber
25th May 2010, 07:44 PM
If the join is falling apart whilst pulling it out of the jig, that would suggest 4 things, flux is wrong, incorrect solder, contamination or insufficient heat.

You say you're getting it to cherry red which indicates sufficient heat, so lets look elsewhere.

Can you post some pics up of the flux, stick of solder and the ends of the blade with the melted solder.

I suspect that the flux and solder is not the right type or that the flux has dried out.

Is the stick of solder easily bent like normal tin solder or is it more like coat hanger wire?

Is the flux fluid or more like a wax type paste?

jefferson
25th May 2010, 07:55 PM
Pat,

So sorry I can't help. Listen to Fred and DJ and do a post mortem - you'll get it right (eventually).

And don't complain about blades - I think I have a bandsaw motor on the way out, much more expensive.

wheelinround
25th May 2010, 09:06 PM
Laymar Crafts (http://www.laymar-crafts.co.uk/tip49.htm)

hughie
26th May 2010, 09:46 AM
Pat if you could post a few pics of the disaster zone we might be able to sort out the problems.
ie the flux container, silver solder packet, and a few shots of the failed joint, a brief run on what you did in sequence.

Push comes to shove you could butt silver solder and not have a scarf cut.

A few check points;

1 when making the angle on each blade, just file of grind it. Do not try and smooth it with sand paper etc or touch it with your fingers.

2 lightly smear the flux on [ not with your finger], it must be wet, wet as in how it came from the manufacturer, If it has dried out discard. It should also be white.

3 fix together so it cant move

4 gently heat, don't burn the steel, take your time. The blade will heat up very quickly anyway.

Assuming the guy sold you the right stuff.It should work

bowl-basher
26th May 2010, 03:46 PM
Don't be a cheapskate Pat, that would look good in your new shed:2tsup:

But I was responding to this statement:

I take your point about resistance welding I think you will find that they also use silver brazing for the oddball ones or in the repair of blades
I had one customer in New Guinea that used to purchase 2-3 kg at a time
just for the repair of blades and tooth replacment
Regards
Bowl Basher

Alastair
26th May 2010, 05:12 PM
:gaah: I surrender!

Attempt 42564316465423132165431345643165464231 failed again. Solder flattened, edges scarfed, flux fluxed, jig and 100mm either way heated, join heated to cherry red, Allowed to cool naturally. Join failed to stay joined even while removing it from the jig!

:frustrated::club::fit::rant::upset::ranting2:


Hi Pat,

I'm no expert, but I have ss'd a few, and while not as smooth as I would like, none have ever separated after soldering.

Feel free to let me know if you are likely to be up North of Hornsby, and maybe drop in, and I'll run through it with you.

regards

Pat
26th May 2010, 09:06 PM
Thanks for that Alastair. I'll keep that in mind.

wheelinround
29th May 2010, 10:35 AM
A friend is coming over today Pat we will be going over SS he does his own BS blades and SS some parts at work reckons he's not that great at it.
Will let you know how it goes.

I want to be able to SS tips on for tools it should be easier as that will be thicker material.

Shame your not closer you could pop over.

Edit 1322hrs :doh: sorry Pat forgot your at Clintons today.

Well friend popped over so I could review technique Ken showed me his way

Grind matting ends of the BS blade only the sides that face each other

Pic 1 fit into jig ...Ken's jig is off his old BS which was 3phase now single and had a but weld device.

Pic 2 Ken then wiped an applied flux and tinned the first bottom bit just enough SS to cover the join area. Applied flux to the top and placed to the join area.

pic 3 finished SS but not ground flat or cleaned up

I have video of the process have yet to edit and fix it up will try load ASAP

Blade was ground and fitted to BS and tested minor guide adjustment made :2tsup::2tsup::U

Ray

Pat
29th May 2010, 08:30 PM
Looks good. I'll let you know if I am up your way again, at a reasonable hour even. Chris has also offered to weld up some blades for me, so between the lot of yous I'll learn how to weld/braze band saw blades:2tsup:

issatree
30th May 2010, 06:07 PM
Hi Ray.
IMHO, there is way to much S/S in the Pic of the Blade.
If you read the way I explained it, in this Thread, I used some " White Out " just either side of the join, which stops the S/S from running.
There was almost enough S/S to do 2 Blades there.

Please, I am not being Critical, just trying to help.

Regards,
issatree.
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wheelinround
30th May 2010, 06:23 PM
Hi Ray.
IMHO, there is way to much S/S in the Pic of the Blade.
If you read the way I explained it, in this Thread, I used some " White Out " just either side of the join, which stops the S/S from running.
There was almost enough S/S to do 2 Blades there.

Please, I am not being Critical, just trying to help.

Regards,
issatree.
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No problem as I said thats prior the clean up but even Ken said when he looked at that point the same thing. I know Ken said that he would normally have a pair of pliers to give a squeeze so that a minimal joint between the skarf was formed while cooling.

nz_carver
30th May 2010, 07:12 PM
Pat mate I know im part Kiwi and we all know things from NZ are not that fast:D

But why not just buy a new blade mate??
I tell you what coz we are mates:U
I will trade you some blades to fit your bandsaw

For lets say your Metallica tickets:2tsup:
and and lunch at the wood show:q

Pat
30th May 2010, 09:06 PM
Pat mate I know im part Kiwi and we all know things from NZ are not that fast:D

But why not just buy a new blade mate??
I tell you what coz we are mates:U
I will trade you some blades to fit your bandsaw

For lets say your Metallica tickets:2tsup:
and and lunch at the wood show:q

:hahaha: Good one Dave. Because I could, I had the opportunity to purchase a role of bandsaw blade and thought "Why not, another skill" . . . Famous last words:doh:

Alastair
31st May 2010, 10:10 AM
Also, it's not just the b/s blades!

Once you are set up and can S/S, you find a host of other things which become possible:)

regards