Gaskets or gunge?

I always seem to have trouble getting a reliable (that is it seals first go) and effective seal on things like the valve chest, cylinder covers or dome flange. What do you use ?

Thanks, Phil

I always use Loctite 574 flange sealer. Easy to use, excellent seal which can be easily broken when you find that you have haven't put things together properly . Old, hard sealant easily removed as well.

Mick

Thanks Mick, do you use it with a gasket or just on bare metal?

Phil

Phil.... Loctite 574 it is designed to be used on bare metal. I have also used PTFE gasket material, especially on cylinder covers and find it good but found the nuts needed tightening up when the engine warms up.

Mick

Cheers John but access to nuts to retighten when hot will be very awkward so have got some Loctite on order from fleabay

Phil

How do you cut small holes (8Ba etc) in gasket paper ?
BobH

Grind the wrong end of a suitable drill square across and put it in the chuck of your drilling machine, put a bit of softwood in the drill vice grain upwards and just punch through the paper. You can use the flange or whatever as a jig. If you're doing a lot, a more sophisticated job is to make up a steel die, for 8 ba make it about 1/4" diameter, hold it in the drill vice bolted down to maintain alignment. I've got a tin full made over the years, but it's usually quicker to just make another than find the tin! Hardening is not required unless you're making thousands of holes.

Edited By duncan webster on 22/11/2015 21:59:34

hi phil,

i test all my cylinder assemblies on air when setting the valves. my machining and skills are very average and my equipment very basic and antiquated. when on test under air, no sealing is used, just metal to metal. make sure you have removed all burrs etc.

on final assembly i add a smear of old fashioned red hermatite, or these days one of the expensive car part copper silicon sealants. i never use gaskets on the cylinder assembly except in one special application that may be relevant to your Boxhill which i can supply you with details if required.

for boiler stuff again metal to metal initially and i then add a 1/64" gasket of the modern type now sold by Blackgates. i mark everything up with engineers blue before the above. the addition of a gasket is a bit of 'belt and braces'. a large inner dome flange will frequently slightly distort when silver soldered to the barrel and needs blueing up and truing/fettling afterwards.

a very experienced miniature loco friend of mine plus boiler inspector uses ordinary silicon sealant on boiler parts bolted together.

hope the above is of some help.

cheers,

julian

Duncan, I like that idea - simple and quick. BobH

To make holes in gaskets, I place the gasket on the component, over one of the holes place a ball bearing of a size or so larger than the hole, give it a light tap with a hammer, put a bolt in the hole and carry on. I actually have a little hammer that I made, one side of which is made of a 1/2" ball bearing, and this is often used for gasket making.

Ian S C

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Laser.

That hole in the middle is 1mm, the one on the outer edge of the same link is 1/2mm and the curved slot is 1mm wide.

Takes 14 seconds to cut this.

I like John's laser idea and have often seen it mentioned. What sort of James Bond machine is a workshop laser ? Any pictures etc ?