Can I silver solder drill rod?

[chucketn]

I'm ready to start the crank for my Woodson Vertical Steam engine. I would like to make it from brass(throws) and drill rod (shaft).
Can I silver solder the drill rod into the brass throws? Materials are chosen based on what I have in the size needed.

Chuck

 

[goldstar31]

Chuck, this is what silver soldering is all about. So long as you have a decent silver solder rod and some borax or better, it should be money for old rope. Give a little clearance for the 'Wicking' of the solder and that is it. Do the usual thing, the solder paste into a bit of water or spittle and cut a little ring of solder to go over the drill rod and blow it up to dull red hot after the flux goes glasslike and touch the ring of solder with the end of a bit of solder rod.
You should be sitting with the job done and ready to work,

Stand back- in amazement!

Cheers

Norman

 

[Swifty]

Just be sure to not get the drill rod so hot that scale appears, will not go well then.

Paul.

 

[gbritnell]

Chuck,
I have silver soldered almost every conceivable combination of metals. That being said I have to ask the question, why do you want to use brass throws for your crank? I would go with 1018 CRS, 1144 mild steel or as a last resort 12L14.
In most cases I would agree with Norman on leaving a little clearance for wicking but when I fabricate and silver solder crankshafts for hit and miss engines I like to keep the fit fairly snug for accuracy. I chamfer the inside and and outside of the holes and fill them with silver solder. This provides ample strength. One other thing that you can do along with the chamfering is to file or mill a small flat on the throw and crank journals where they locate into the webs. This will allow the silver solder to flow inside and strengthen the joint while still allowing for a nice tight fit of the pieces.
gbritnell

 

[bazmak]

Its usual to quench a silver joint to remove flux,which also hardens the drill rod
could be a problem if its brittle.Regards barry

 

[gbritnell]

You really don't have to quench to remove the flux. Just wait till it cools and boil it in water.
gbritnell

 

[barnesrickw]

Will it boil in water when you quench it?

 

[XD351]

Any one tried ultrasonic cleaning to remove flux ?

 

[goldstar31]

I certainly agree with Gbritnell about tolerances etc. I was writing 'generally about technique.
Regarding the removal of flux it is probably no great thing to remove it with a penknife or something sharp but flux should easily be dissolved chemically in any number of easily obtained acids. The one which comes to mind is Brown sauce which is vinegar or acetic acid. If push came to shove, a nice dunk in coco cola which is dilute phosphoric acid. Whatever it is, removal is nothing to get worried about.

As for cooling, it depends on whether one wants to temper the steel or not. Dunking it in cold water should give a glass hardness and I doubt that this will be desirable. You could of course, harden it from red in oil or- might I say, your urine! And I am not-NOT joking.

Regards


Norman

 

[kvom]

I've been making my cranks with drill rod and securing with loctite And pins. No danger of heat warpage.

 

[goldstar31]

I've been making my cranks with drill rod and securing with loctite And pins. No danger of heat warpage.

Well 'Yes and No'!. It all can warp- and does. Certainly, you can get some funny results once you have cut into metal- any sort of metal.

I recall making a Westbury Milling Machine and doing the headstock. All was fine and dandy, until I split it to clamp on the column-- and it nipped.
Again, the late and lamented George Thomas made a Universal Pillar Tool and he hit the same problem. Actually, the castings now are Mark Two's.
Same problem with the Quorn- yep, mine nipped up.

Some years ago, I took a small lathe bed in for 'Blancharding' and the feet had to be levelled before the top was done.

Sorry, but metal is left out after rough machining to 'normalise':hDe:

'Fraid it is something which is inevitable. You may be able to 'live with it' but it is there.

 

[gbritnell]

There is nothing wrong with making a fabricated crank. Personally like I stated earlier I prefer making the throws from some type of steel. I have found that the reason for warping after soldering is that one side of the crank gets soldered first then the other. When the through stock from the shaft is cut from between the webs sometimes and I say, sometimes, the crank will warp. One way to help prevent this is to solder both sides and then bring them both up to the melting temperature of the solder. Except for the largest crankshafts this can be done with 2 propane torches. What this does is allow the solder on both webs to harden at the same time and generally this will prevent warpage. If when removing the center material some warping is detected it's generally always in line with the shafts, hardly ever is there a twist in the crank. To remedy this I put the crank in the lathe between centers and check it with a dial indicator, noting the high spot. If the high spot is toward the throw, main shaft area is narrow, then take 2 wedges like 2 morse taper shank removal tools. and slide them into the crank area to spread the webs. If the high spot is toward the main shaft then use a small clamp on the webs and squeeze them together. Either way at first apply a reasonable amount of pressure and then reindicate. If it hasn't moved then you will know how much pressure to apply the second time. The material will generally flex and spring back so enough pressure has to be applied to get it to move.
As far as removing the flux all that needs to be done is to boil some water and insert the soldered piece. After a couple of minutes all the flux will have been removed. There is no need for acids and chipping. If you have never tried it then please do.
gbritnell