Hi guys - as a well known MEM 'character' might say - 'How ya'll doin'
Not much actual progress on the Throp to report about but it has been a bit of a 'testing' time as you will see
When Simon first raised his concern over the possible failure of the JB Welded soft jaws I didn't cursorily dismiss it out of hand despite my confidence in the product. I still think they will hold way beyond their intended use but then Kerrin raised the question of machining allowance (I realise now that I read that as had I used a conventional fixing with JBW used cosmetically so something I did not actually answer - sorry K) I began to muse that whilst I had great confidence in the product based on previous use I did not actually know what sort of situation JB would break down at - or tolerate.
I had this thought in mind as I began to think about the pipework required and how I would assemble it - above and below the base - and the need to make sure the component parts could be held in their correct attitudes whilst silver soldering. Musing on some complicated fixtures the thought occurred well if it was all assembled with JBW then all that could be overlooked. Question was how good would JBW be in that application.
So this is what I've been playing with before I get to the pipework proper - hope it will answer any lingering doubts, as it certainly has mine.
I intend to use 10mm dia commercial copper pipe and copper elbows for the pipe work so the potential of joining these with JBW required to be established. First off was to silver solder a plug and a connector into the respective parts. The fixing area was abraded with coarse emery.
A liberal coating of JB applied to both surfaces
This was left overnight on a radiator to cure and then left for a few days before testing
Filled with water by syringe it was then pressure tested to 50 psi then at 100 and 200 psi .....
.. to the gauge maximum of 300 psi. (the gauge was checked against the boiler testers gauge when the WaW boiler was tested so I'm happy that's a fairly accurate reading)
Left at that pressure while I had a cup of tea only a slight creep back of the needle occurred but most importantly no evidence of water was found on the blue paper - a very good tell tale for this purpose. I am more than satisfied that this will be more than adequate to handle any pressure this engine is likely to see so I will use JB to finalise the pipework connections in situ.
Ah but you ask what about temperature effect - well....
Realising the Kerrin was asking if an allowance was required in machining as opposed to a primary means of holding I began to think about the condenser flanges which were fundamentally just 'glued' in. Time for another test!
An old piece of mild steel bar was faced off (with that new carbide cutter - a nice finish, I think you'd agree) and some holes put through - tapped 1/4 x 40 on one side and on the other counter-bored 12mm diameter. Three holes (two were 'spare') were then machined to the same dimensions as those for the flanges in the condenser and three 'plugs' made to suit. All had a pressure resisting surface of 12 mm diameter - the three 'feet' on the central plug was to ensure this remained.
The fits are 'loose' but not 'rattle' fit - .05 / 08mm (2-3 thou) on diameter
A nice coating on all surfaces ..
... and once cured the fillets fettled much the same as those on the condenser.
Done at the same time as the pipework this was well cured before testing was carried out yesterday.
Each test piece was done in turn and taken up to 300psi as before. Each test was left at 300psi for several minutes with no significant pressure drop or leaks occurring, the paper once again bearing witness.
Once all three had been tested at room temperature the exercise was repeated again with total success but this time allowing the whole bar to come up to the temp of boiling water
The bar after the test
JBW appears, using a scriber as a probe to have suffered no degradation so I think I can safely say that for me I am more than happy to continue to use this product in the manner described - for the task in hand. This was not done in order to advocate it as some kind of magic cure all but I do think it has great potential in 'casting assimilation' on engines that will see little work. How far someone would wish to take that is down to the individual I guess but I have satisfied myself that it is as good as I thought it is.
Well, I realise they are not as scintillating pics as perhaps some would have but I hope they serve to inform - hope you weren't too bored.
Now, I guess, I can continue on that pipework
However whilst this was curing I did take the opportunity to have a side step for a couple of days
.....
Two cranks for a slowly progressing pair of 5cc diesels - more on that perhaps a bit later
'Thatsit frum tha ol shid taday'
Regards - Ol Tug
PS I think I should point out I did this in reverse to how it's described - with the success of the testing in boiling water I felt there was no need to do the same with the copper pipe parts.
