Reconditioning a Relmac lathe

[irving2008]

Removing the remains of the 1st attempt was easy - didnt even have to melt it out as there was hardly anything in there, but what was there showed promise - nice n shiney and clean surfaces



So cleaned it all up and re-assembled with a blowhole this time and left it out in the hot sun for 4 hours while I popped down to Argos for a better burner - the new one is 2300W and a much wider burner so it melts the metal in about 6 minutes against 18 or so before.. so much hotter (and you can buy the canisters for it too!)

So the fire-cement appeared to be set, it was rock hard and the whole lathe was hot to the touch from being sitting in 26degC sunshine for 4 hours so thought I'd try again...





As you can see, not a great success

Two mistakes... firstly my impatience, I assumed it had set but clearly was only on the surface and not right through - it needs that 24h or so... and secondly, I made the end dams not from ally foil but from pieces cut from an ally foil dish 'cos its thicker and easier to handle. But to get it round the shaft I cut fringes and bent them over. Big mistake, because it prevented the fire-cement sealing to the shaft properly. As a result when the pressure built up the fringes lifted and allowed the hot metal to spurt as you can see - it was quite a loud bang and fortunately I was standing on the other end... The third pic shows the 'hole' where the pressure built up, probably due to water vapour from the fire-cement. the air blow hole worked ok till it blocked up tho :)