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I've used citric acid on all of my soldered parts with great success.... cheap to buy and very safe to use.... just need to be a bit more patient.
 
Here is a question I have never asked before. I would like to do some more finish sanding on this part to clean up the last of the file marks. The part has a really odd shape. I have a roll of #280 grit carborundum cloth x 1" wide that I use for cleaning up turnings in my lathe, but it is of course pretty floppy stuff. Ideally, I would like to buy something like a 3/8" wide strip or 1/4" round of this grit, but rigid so I can use it the way I would a file. Somebody must make a thing like that, but I have never seen it. The closest I have seen to it is way back in the day when I was a junior draftsman we had something similar, a flat wooden strip about 4" long x 1" wide with "tear off strips" of sandpaper on it for keeping a deadly point on our drafting pencils.--HOLD ON--Google is my friend. I just found something close to what I was talking about.--Come to think of it, I think my wife has something like that for doing her fingernails.
https://www.amazon.com/dp/B00G14F41E/?tag=skimlinks_replacement-20
 
Last edited by a moderator:
Well Sir--I didn't even have to leave my house. I went upstairs and begged an emery board from my good wife (for filing fingernails). I hunted around in my shop and found an ignition points file, and found a new Scotchbrite pad while I was looking for it. The resulting finish is far from being show quality, but it is "good enough" for now. I will consider using a bit of filler and painting them when all is done, but that's a long way off.
YWaXVH.jpg
 
Looks good Brian,now for the rest of it. I made the Stuart from castings
and thought about making the twin by fabricating the castings and upscaling
X 1.5 of course. Never got off the ground.My silver solder Mapp torch is waytoo small.Will have to look at oxy/acet for my steam loco
 
Having made one of the soldered "stands", I now have to make a second one. What did I learn from making the first one. First of all, use a bigger torch head.--I can do that, as I have a larger torch head available. Secondly, when soldering on the "feet", don't hold the bar that ultimately becomes the "feet" endwise in a vice.-As soon as the brass gets hot enough to solder, the brass bar will deform from the pressure of the vice and go all wonky. That is why one foot on the finished stand looks fine, while the other foot has a definite wedge shape to it. I think those are the only major things. These are about the most complex shapes that I have made from brass bits silver soldered together.
 
sorry to jump in late on the pickle solution, but for brass and copper I have used in a quart jar, fill almost full with distilled vinegar, 3 tablespoons of kosher or non iodized salt (do not use table salt - USA adds iodine to it other countries probably do to)and just a good guess amount of hydrogen peroxide maybe 1/4 cup? just enough to fill up the quart jar to the neck

I will often microwave the solution for a couple of minutes to get it hot or warm. then drop the brass or copper part into it. in just a few minutes brass will turn that nice copper pink color and solder will stick like crazy.

I got this from a jewelry making web site. cant remember its name. but it works good for me and is cheap and easy to make
 
werowance--that may be good for pickling before you silver solder. I was looking for a pickling solution to clean things up after the soldering was finished, to remove blackening which is almost impossible to get out of any pitted areas. The citric acid worked great for me.---Brian
 
I am really impressed with how well this citric acid works as a pickling solution for cleaning up parts that have been silver soldered together. I had tried mixtures of vinegar and hydrogen peroxide before (as recommended by somebody on one of the forums) but it didn't seem to be very effective. Now I'm wondering about something else--I see that builders of model steam engines don't seen to use flux on their parts which they are silver soldering together. Instead they soak the items being soldered in a pickling solution before they silver solder them, and don't appear to be using any flux. I have always used flux on the parts I am going to silver solder. Who can shed a bit of light on this subject?
 
I am part way through the second assembly tonight. My soldered joints are still lumpy, but I did get a lot better "flow out" of the silver solder using the larger torch tip. I would have been finished today, but helping babysit a two year old grandson and having a sore back has cut into my day quite a bit. I hope to finish the second assembly tomorrow morning.
KsIqtB.jpg
 
I was warned that the citric acid pickling would leave a very definite mark on any part of the steel which was not completely submerged in the acid bath. In the interest of science I stuck a piece of steel in the bath I have, with part of it not submerged. Who-ever told me was absolutely right. It leaves a very visible demarcation line, which can not easily be sanded out.
QF83WH.jpg
 
I didn't show this set-up for slotting the stand when I posted about the first one, so I'm showing it here. The 1.5" diameter is held in the 3 jaw chuck on my rotary table. It's a bit hard to see, but I have a machinists jack under the outboard end. The legs are set to "level" with my machinists level. A hole is drilled thru to 7/16" diameter at each center of the slot, then I plunge thru with a 1/2" endmill at each end, then plunge thru every 1/16" then take one complete pass with the endmill down full length so it is cutting the top and bottom all in one pass. You will notice with this stand that the "feet" are equal in thickness and there is no slant on the top of either foot. That is because I found a better way to fixture the feet before I soldered them on.--Yes, an old dog can still learn new tricks. I still have to machine and file my lumpy solder joints before I part the stand off from the main 1 1/2" diameter, but I think I will save that for tomorrow.
VVD7la.jpg
 
In the interests of your citric acid tests, I tested a cheap charm bracelet that was found lodged inside our washing machine (thanks to the kids). It was a 'snake' type bracelet rather than a simple chain and was likely chrome plated, but was rusted to the point it wasn't flexible anymore. 12 hours in the pickle, which did produce some light bubbling, all the rust was gone and the bracelet was nice and flexible again. I could have replated it but the catch was broken so the wife threw it out (before I thought about taking a photo). Seems like useful stuff.
 
No work on this project for a couple of days. I have a severe case of Sciatica and the pain in my lower back keeps me from standing at my machines. Fortunately it doesn't bother me when I'm setting down, so I can still do cad work. I did buy material for the engine base, but haven't done anything with it yet. I am anxious to get the last stand finished and move on to machining the base.
 
Brian,

I have watched a number of your inventive builds over the last couple of years and admire the way you develop solutions to the problems/issues that arise.

I had a wander round a charity bookshop today and came across a two volume set of books which I think would keep you entertained for hours.

The books are entitled:

Ingenious Mechanisms for Designers and Inventors. Volume 1 and 11. It is an American book copyrighted in 1930 by The Industrial Press of New York City. The copy I have dates from 1946 (Seventh edition).

Topic titles include,

Cams and their applications
Intermittent Motions
Tripping or Stop Mechanisms
Reversing Mechanisms
Overload Relief Mechanisms
Interlocking Devices
Reciprocating Mechanisms

and so on.

There are over 1000 pages in the two volumes.

I'm sure if you could find a copy over there you would find lots of new and interesting mechanisms you could possibly build.

Regards,

Colin
 
I have both Vol 1 & 2 in pdf format but too large to post here, PM email if you want a copy,

Cheers
Andrew
 
 
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