o-ring seal installation technique: Got the cylinder OPEN

Reid · o-ring seal installation technique: Got the cylinder OPEN

How to fit o rings, please?
Groove shape, depth, width in relation to the ring.
What kind of ring material is most suitable?

Aim: seal the Wilesco piston; also seal the piston rod (there is no gland at present),

also desire to seal the piston valve's ends
and also to seal the piston valve midsection too if that is feasible.

Q: Can a ring slide back and forth over a steam port hole?

image from the Wilesco site

Roly Williams' brilliantly cross sectioned Wilesco D16
driven by clockwork Meccano

http://www.youtube.com/watch?v=FiSuz2Dyrbk

Bogstandard

Hi Reid,

I have disassembled one of these units many moons ago to try to do exactly as you are asking about.
You could fit a ring on the piston, but forget about using any in the centre section of the piston valve area.
An o-ring will not go over an inlet or exhaust hole. But in this situation, on the piston, it should not be not be a problem as the piston doesn't travel far enough to to let the o-ring reach the holes.

The type to use are either silicon or viton. Viton is the more hard wearing, silicon should not be let anywhere near WD40, they are destroyed by it. Care has to be taken with DuPont's Viton, it should not be allowed anywhere near a naked flame. It produces a nasty acid (I haven't got the name handy) that destroys flesh and bone tissue, even in minute amounts, it usually means the affected part is amputated. Fire fighters learned the hard way when attending car fires. A lot of seals on modern engines are made from viton.

For a small engine such as yours, the groove that it sits in should be a maximum of 0.002", preferably 0.001" too shallow. Otherwise you might find that the friction of the ring pressing on the bore will not be easily overcome. The groove section is just a standard square, the width being about 0.001" wider than the cross sectional diameter of the ring.

I came to the conclusion that because the engine was made to such low tolerances, it wasn't worth the effort for what gains, if any, were possible.

John

CCairns

Reid

Thank you so much for this invaluable guidance.

I have easy access to buna-n rings for trial work.
Do you think they'd serve long enough to show results at least?
Then I can order viton rings if the basic rings work out.

Q: How would one best go about pulling the cap off the Wilesco cylinder?

This one seems to be a tamped-in cap? Perhaps cemented?
I can't see any sign of solder here.

Plan unless advised otherwise:
soft solder a nut or T-nut to the cap, make a slide hammer of a screw
and a slug of something weighty
and knock it out that way,
with some heat as an aid to loosen any cement that may be there.

Bubba

Reid

Yeah sir, I know welch plugs, being a Welch myself, though not likely a relation to those early auto men.

It's a cap. Swedged or not, it must pull out. I'll do the slide hammer thing first, I guess.

Bogstandard

If you are V-E-R-Y (said a dozen times) careful, you can use the piston and rod to take the top cap off.
Find a piece of plate that fits nicely into the slot of the piston rod.
Support the outer tube leaving clearance for the cap to come out (another piece of tube in a vice) and gently tap on the bit of plate in the fork of the piston rod. If it doesn't start to come out after several light taps, stop. Do not force it. These units are sealed for life, and are designed as throw away items. Be careful about twisting the plate in the fork of the rod, they are very fragile and liable to snap off. I have seen these units from kits where one side of the fork was snapped off while still in their packaging, before they were assembled into engines.
Put heat nowhere near it, the solder is very soft and the whole lot will fall apart. I know, I've done it, and it was a pig to get it back together in the right positions again.

John

Reid

Thank you John, thank you!

Quite sure then that the piston end strikes directly onto the inside of the cap.
Close examination here seems to indicate as much.
I would need an x-ray if not for your vision. Thanks, savior.

If I muck it I'll get another assembly through ministeam.

The boiler, this crappy-solder that Wilesco employs, continues to generate copious quantities of metal flake, as much as always.

Two days ago: distilled water left in a clean boiler overnight

It's the solder, not the brass: the particles are perfectly silver and are of large size.
When the boiler is 3/4 and steam is drawn at high rate it is quite certain now that some of these particles are getting into the steam line.
The wearing of the piston valve is evidence of a near constant supply of -something- rough enough to score,
for there is no lack of good oil here. Am sure, watching the picture window Wilesco sight glass, that the solder flecks get all the way to this engine.
In result, after some thirty hours or so (guesstimated) operation,
compression seals are not near what they were when the engine was new.
In result, under heavy load and especially at stall, there's quite a waste of steam in the engine.
I hope therefore to at least seal the power cylinder.
Will order a spare piston valve from ministeam, along with a long-needed crank disk that'll run true (mine is cockeyed).

I may break this more before I learn better.
My head is hard and this Wilesco brass is soft and as you say: brittle.

Thanks John for telling me better.
The challenge though is to make the most of this sow's ear.
I'm willing to make many errors before softening my brain
and then accepting that this is a low quality toy engine (it is that)
and that it should not be meddled with, not too much,
unless one needs a non-productive hobby---or obsession.

Bogstandard

Reid,

If you look carefully at the vid and pause it when it shows the cutaway, you will notice that the edges of the piston will contact the flanges of the end cap. A perfect place to come into contact.

John

Reid

Reid

An hour ago...

same vid, bigger player

Bogstandard

well done reid

john

mc_mc

Ouch! Mind those fingers.

Nice to finally see inside of that thing, can't wait to see how you improve it. Is there anyway you can think to improve that cap to make disassembly easier next time and also retain the steam tight seal?

bessytractor

good to see it came apart ok for you. At least we all know how to do it in future if necessary

steamyjim

Well done Reid!!!!!

jamespetts

You could always wear latex gloves...

toxx

... wow, Reid, great work!

It's a pleasure as always to watch your progress!

Reid

I could always wear latex gloves...he says

Dear friends and moral supporters,

thank you for cheering me up.

I made a Philisophical video last night before pooping out again.
Put to upload, whilst I slept the power failed so I will upload it again.

For those of you who can't see video or even stand my stupid stylings (understandable that!)

,

Here are the facts and the -guesses-.

Paint stripper of this sort: goes right through latex gloves pretty fast,
but even with good thick gloves I could not manage the manipulations for the camera-showing.

I had rinsed the assembly but not nearly well enough--intentionally left it full of the stripper in case it all needed to again into the bath.

But behold!

First tap showed the cap to move! Hooray!
So's I sets up me camera mit der closer-upper lenzer.

I figured I'd get it all apart faster than the stripper would take my skin apart;
one has to have had methylene chloride bide a while on his or her skin to know what it feels like coming on:
something like cold pepper (?!) plus acid, it's really hot yet cold, that burning sensation,
and is hard to wash off once you feel its biting because by then it has gone through the outer skin.

But, ho! The cap came right off. So clever, Reid! But no! Reido had burred the shoulder of the rod! I could've cut out all that time wasting footage ,
but no sirs! I've a devilish sense of humour even while it's digesting mine flesh.

-----

The new video will demonstrate an easy sure way to gain some free power.
This gain pertains to piston-to-cylinder end clearance (there should be next to no cylinder clearance.
I'm not speaking of piston fit, but of cylinder end clearance.

The cup-like cap will be filled to flush with soft solder (just as a means to make it a solid cap, nothing to do with attachment)
And by that simple expedient I will gain some steam economy= free power.

The o-ring will be fitted. It will become the new bearing surface for the piston (we'll see how/if that works out long term)

The cap will go back in the way it came out, with a tap and then a drop of wicking-grade Loctite.
I may elect to fit three little taper pins, just quills poking in a smidgeon, through the cylinder end into the cap,
pins left long so they can be pulled out by pliers,
just to really ensure the cap never explodes out of its own goddam accord.

video of last night in a few hours.

mogogear

Once again your sardonic narration is destined for ans Oscar................. or a Felix

Great to watch you work... and work... and work... at least you didn't bleed..What you do for your audience is admirable

Reid

2008

1923, 2008

toxx

... as a gland you could try a piece of tight fitting silicone hose as a "sleeve". That might work.

Nick

I just went through this whole thread and watched all the videos. They were very enjoyable.

I will be watching this thread to see your o-ring and any other ways you fix these problems.

MooseMan

Ah Mr Welch, I do so enjoy your videos....I've got a whole collection of 'em, one of these days I will make a "best of Reid" DVD.

As for the paintstripper......please don't get that shit into your bloodstream mate!