Minnie seal problems

[David Bothwell 1Participant @davidbothwell1]

I am having quite a bit of trouble with getting a good seal of this (Minnie 1" te) cylinder to the boiler. I have used 1/64th sheet gasket and also a sealing fluid on both sides, but air is escaping around the sides of the cylinder. I made my own screws from bronze 6ba, but reverted to stainless steel bought ones. I have/am considering either using bigger (5ba) screws, or doubling up on the gasket, i.e using 2 sheets! It pains me to admit it but I have broken heads off 2 screws (arghh!) so it has to come off! ANY suggestion gratefully accepted.

[David Bothwell 1Participant @davidbothwell1]

Sealing cylinder to boiler

[nigel jones 5Participant @nigeljones5]

apply Loctite 660 – it wont leak again!

[JasonBModerator @jasonb]

What sealant did you use

Did you machine the underside of teh saddle to boiler dia plus twice gasket thickness of to just boiler dia?

[David Bothwell 1Participant @davidbothwell1]

Thanks Fizzy, Jason I bought the model as a part made project I realised the underside of the cylinder (gunmetal) was a very bad fit to the boiler, so I set about putting it right with a rotary tool and sandpaper wheel. Unfortunately I did not realise how soft and easy the gunmetal was.Cut a long story short I have had to solder a piece if brass to the base which I though was a much better fit! I hop you are not horrified by this!!?

[nigel jones 5Participant @nigeljones5]

nah…..the other less reversible easy fix is to put it in place on a bed of jb weld,either wat it wont leak ever again!

[JasonBModerator @jasonb]

So it sounds like you have made the saddle a good fit on the boiler dia, if you now add 0.016" of gasket then the saddle will make good contact at the sides but not in the middle.

Options are to not use a gasket and go with a modern sealer as Fizzy suggests, or increase the radius of the saddle to take into account the gasket thickness which is best done by finding some abrasive sheet that is as close as posible to 0.016" and wrap some round the boiler. Now just rub the saddle over this in teh vacinity of where it will eventually fit until you have sanded the whole underside.

Going upto 5BA won't be a problem but you may need to use 6BA heads as there is very little room particularly front and back. To save snapping weaker bronze or stainless screws use steel ones first of all to pull thing sdown and then test once sealant has set. If all is OK then replace steel screws one at a time ading a bit of sealant to each new screw.

[David Bothwell 1Participant @davidbothwell1]

Many thanks for those excellent replies, upon which I will shortly be acrting of course, bank holiday may slow any progress, shops closed and all that. Other thingsto attend to on the model

[David Bothwell 1Participant @davidbothwell1]

Just out of interest just checked and one of the main suppliers of bolts does 5ba stainless with 6ba head, just ordered some

[nigel jones 5Participant @nigeljones5]

looking good…that Locomotive of yours!

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