Hi,
Try practising with a short stub of copper, makes it possible to see inside the pipe and gauge how tight it is when the olive 'prints' through on the inside of the pipe.
IMO the way to a reliable compression joint is use a copper olive, don't let the pipe bottom out in the fitting but pull it out a fraction, and don't overtighten.
cheers, Pete.
The _continuing_ problem in this country, is the lack of standardisation. If only we just had the metric system here, we wouldn't have these problems. A memory from the motor trade: At one time, there were three different thread types used on a BSA Bantam m/cycle swinging rear fork spindle: BSF, UNF fine, and Cycle. Another memory: The early Morris Minor cars (split windscreen, sidevalve engine) had mostly BSF threads, but the gearbox had Metric fine threaded bolts. I could go on!!!
I think that the problem with compression joints is the possible mix of English (1/2 inch, 3/4 inch) and Metric (15 m/m,
22 m/m) sizes. I only have a small amount of DIY experience, by the way.P.S. I've just changed the partition beads, and the two inner cords on a small sash window. I wonder how much I would have been charged for this by a professional person?
Sylvain.
Partition beads... parting bead? Anyway, well done - this is the sort of thing that many people would have DIY'd a while ago. Now I hear that sometimes people change the whole window 'cos a cord has broken!
On Tue, 09 May 2006 21:45:03 GMT, "Sylvain VAN DER WALDE" had this to say:
Surely adding the metric system simply adds MORE non-standardisation? All these BSF, BSW etc predated ISO metric! Even the metric system has its own variations as well!
Nuffield group used oddities for some things - cycle threads with BSF hexes. Could be those threads are close to metric fine. First really noticed them as big end bolts on an MG XPAG engine.
I wasn't completely sure about this. You probably are correct (the clue being in the English spanner sizes). The threads were certainly very fine. Now BSF isn't a particularly fine thread, so using a Cycle thread may not have been such an odd thing to do, after all
Sylvain.
The story I was told by my father was that Morris originally made cycles. And at that time many such engineering shops made bolts and nuts in house. When they started making cars, they carried on with the same threads to avoid the capital cost of buying all new stocks and dies, etc. But changed the hex to BSF sizes so the local blacksmith had tools that fitted.
Could all be an urban myth, though. But he did serve an engineering apprenticeship at about the time Morris started making cars.
[on compression joints]
That's absolute rubbish.
I only have ptfe on taper or parallel thread fittings. None at all on compression, it just isn't required.
Cheers
Paul.
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