Member postings for gary arthur

Aha... yes indeed Paul.

You'll see in my post above (the one with the pictures) that I say 'the bottom half of the firebox needs to be fixed back on'.

What you are looking at above is only the top half of the firebox, which I took off to drill and tap the bolt circle for the top plate. The bottom half (which I'll be putting back on as soon as I have made some finishing touches to the top plate) has the bottom half of the firehole plus an opening for the ashpan below the grate already roughly cut out.

This is all currently in very rough form for a test firing to see if the boiler will actually run on solid fuel, but it will have a makeshift cover to close the firehole as you describe. I'll post pictures once it's back together, and if it all works I'll tidy up all the openings etc which are just roughly cut out at present, and fit a proper door.

Cheers,

gary

Thank you for this, Bazyle.

I was planning on trying charcoal first, but in response to your advice will speak to my friend about some steam coal.

I spotted through the holes in the top plate then drilled and tapped (M4) the bolt circle in the top half of the firebox body:

I then took the firebox top plate off again and silver soldered the spigot for the bottom of the boiler on to it. Believe it or not my Sievert torch started playing up (again) during this operation and would not heat enough to melt the silver solder (which was cut into small pieces laid around the join), so I put the assembly into the woodburner in our living room - which had the assembly red hot and the silver solder flashing round the joint in no time. Dubious practice, but I got away with it! The join isn't the best, but it's actually better than it looks in this photo:

And here's where it's at currently - the bottom half of the firebox needs to be fixed back on, a few more tweaks made and it will be ready for another try with solid fuel:

And if I just can't persuade this little boiler to run on solid fuel, none of this work will be wasted as the firebox will easily convert into a meths burner housing.

The firebox top plate and spigot are now done and are ready to be brazed together and fixed to the main firebox body with M4 screws:

Edited By gary.a.ayres on 11/12/2018 22:35:44

So...

Back on the boiler. Or I should say the firebox as the boiler itself is pretty much finished.

The test firings on gas and methylated spirits went well and raised a good head of steam. However, not so the solid fuel test using small pieces of hardwood in a roughed-out firebox, which failed to produce enough heat. Not to be deterred (not yet, at least), I'm now in the process of modifying the firebox to make it smaller and more compact to keep the heat near the base of the boiler, where it should be. Again, I'll start with a rough trial version in case it doesn't work. No point in wasting time!

However, in such a scenario the top plate of the firebox could be repurposed for use on a meths burner so there's no reason not to make a proper job of that from the outset. That's what I'm doing - or trying to do - now.

First, I cut a small piece off an empty oxygen cylinder from a portable oxy-mapp kit to form a short spigot (it can be seen in rough form in the first picture below). This will be brazed on to the firebox top plate and will fit up inside the bottom collar of the boiler as the conduit of heat from the firebox. A strip of carbon gasket material wrapped around the spigot will form a cushion and seal between it and the boiler.

The top plate is made of 5mm mild steel plate. I used a hole saw to make the initial hole for the spigot then proceeded to bore it to size with a boring head. I plugged the boring head into my new Sieg SX2.7L mill using a 2MT to R8 adaptor, only to realise that the thread on the drawbar of the machine didn't fit the arbour of the boring head. It was Sunday night, and I had neither the wherewithal nor the inclination to make a new drawbar. Rather optimistically, I gave the setup a go anyway. It worked at first, but as the hole enlarged and the radius of the boring head extended, the lateral forces generated pulled the boring head out of the quill. Not good.

Fortunately, my customized 'drill press milling attachment' (with a drawbar which fits the boring head) saved the day:

This contraption has raised an eyebrow or two in its time, but it has on more than one occasion got me out of a pinch and is actually quite good, especially as the drill press which powers it now has a three phase motor. And there are occasions when a bit of belt slippage is no bad thing...

For details of its workings, see this video:

With the central hole bored to size, I roughly sliced off some of the steel plate with my Evolution Rage mitre saw (wouldn't be without it) to make it manageable, and then back to the Sieg SX2.7L to cut the top plate to just over external diameter using a rotary table and small endmill. I'm finding I really like this mill - for a smallish machine it fairly hogs the metal:

Cheers,

gary

When I was in France the week before last I found some of this in the supermarket - alcool a bruler (alcohol for burning):

It's 88.4% denatured ethyl alcohol - in other words, I think, methylated spirits.

It's clear and colourless and smells quite sweet rather than the more mineral smell of meths. It's billed as for use as a cleaner, degreaser, solvent and fuel for spirit lamps such as those in fondues. I tried it out on one of the mamods and it did the job but I haven't fired that one on meths yet so can't make a side by side comparison. I'll try it on my boiler at the end of the year when I have the 'pre-Christmas' out of the way. I'm guessing it will be pretty much the same as meths bearing in mind the active ingredient is the same.

The main thing is that at 1 euro 92 cents per litre it's a fraction of the cost of meths in the UK, so I bought four litres of it...

I'm part way through altering the firebox to a design which I *hope* will make it more conducive to running on solid fuel.

However, I have some other projects I need to temporarily turn to and they may occupy me right up to Christmas so there will be little for me to say about the boiler in the interim. I'll pick it up again when I have dealt with the other things, and post some photos at that point.

Meanwhile, and entirely separately from all of the above, I just treated myself to these two little gems - Mamod SE1 and SE3:

Thanks Jason -

Yes. Amazingly, I still have some lumpwood charcoal left over after a Summer of endless barbecues, which should fit the bill nicely with paraffin to start as you say.

Will think about your air line suggestion, and how I might adapt it to my own peculiar ways. You have given me an idea...

Cheers

Paul -

thanks for this. I'm aware of the issues you have outlined.

I didn't use an electric blower. What I did use was a small mouth-blown blowpipe (like the 'boufadou' which is used for the household fire in Southern France) which flared up the fire when I was using it but it didn't last and the fire soon went down again. I just thought I'd try it to see if it worked.

I have in fact now installed a steam blower which showed some signs of working and it did pull the fire but the whole thing just didn't get hot enough. I am reluctant to go down the electric blower route but I can see that one might make all the difference.

Once I have modified the firebox (and a better grate is part of my plan) I'll try again but I can see that I may have to decide between getting an electric blower or just using meths, which I already know works well. That said, with a better-designed firebox, the right choice of fuel and a bit of perseverance I may be able to coax enough heat into the fire using the blowpipe to get the steam blower to kick in. We shall see...

Cheers,

gary

Edited By gary.a.ayres on 17/10/2018 06:42:25

Edited By gary.a.ayres on 17/10/2018 06:46:05

Edited By gary.a.ayres on 17/10/2018 06:47:18

Not so good today.

I tried firing the boiler on small pieces of dry hardwood, but it didn't burn well. I'm pretty sure this was down to the firebox design (different from that seen in the video above) given the small size of the boiler and the fact that it only has five tubes. The boiler just didn't get hot enough. I'd like to be able to use solid fuel so I will persist, and I have already begun with some radical modifications to the firebox which I think should help.

Not the end of the world if I can't sort this, as it runs fine on meths, but I'll carry on for now and see how it goes...

I did a test firing on methylated spirits this morning. It seemed to go quite well:

@ Paul -

Many thanks for your kind comments. The basic design is from Stan Bray, but I scaled it up to x1.5 and there were areas on the original plans which were unclear so a bit of creativity (and consultation) was necessary. Yes, it does feel good, especially after all the trials and tribulations!

Maybe it isn't priming that can be seen in the video... I have seen one of Keith Appleton's videos in which he shows a boiler priming, and I thought it looked kind of similar. I'll look into it a bit more...

On the quick release of pressure - yes, I did wonder afterwards if I should have done that! Next time I'll release it more slowly, but now I'm glad I did it this way just the once (assuming the boiler wasn't damaged by it) as I'll be able to watch that spectacular whoosh of steam on the video whenever I like. 

@ Geoff -

Yes, I have noticed that many more people build engines than boilers. I can certainly understand that - I found this process quite stressful, worrying about leaks and so on. Also, the heat required for silver soldering it all together is not pleasant to work with. However, it's satisfying when it's done and there's something alchemical about the transformation of water into all that powerful steam. I encourage you to go for it.

I haven't built any engines yet - that's next up after I get the firebox for the boiler sorted out. The only reason I started with the boiler is that I hated the thought of building an engine and not being able to run it on steam!

Edited By gary.a.ayres on 08/10/2018 10:27:27

Edited By gary.a.ayres on 08/10/2018 10:28:14

Edited By gary.a.ayres on 08/10/2018 10:29:07

Julian and Neil - thank you both!

It was sometimes fun, and sometimes stressful, but experiencing those blasts of steam has made me very happy.

Thank you both for the advice you gave me along the way...

Edited By gary.a.ayres on 07/10/2018 21:14:00

A major staging post achieved. First steam!

Edited By gary.a.ayres on 07/10/2018 20:19:54

Second water pressure test at 1.5 x WP successful

All fittings were in situ apart from the steam pressure gauge and the safety valve.

On to the first steam test next, using gas to fire it with.

Chimney silver soldered on to cap:

A little bit of progress this evening after a major episode of DIY in the house.

All fittings (apart from the safety valve and the steam pressure gauge) are now in situ for the second hydraulic test at 1.5 x working pressure:



Apologies for the somewhat fuzzy picture. I'll carry out the test at the weekend. The cap and chimney are not yet silver soldered together - the chimney is resting in a circular rebate which I cut around the central hole to approximately half the thickness of the cap. My idea is to give the silver solder somewhere to flow into. Any advice anyone can offer on how to silver solder brass without ruining it will be most welcome!

The photo below shows a close-up of the water level gauge. Fitting it was easier than I expected, though I won't get too cocky until I have seen it not leaking under pressure. I had to make a 1/4" to 5/16" adaptor for the top bush due to a mishap back when I was silver soldering the boiler. It seemed to work ok, but time will tell.



gary

Lots to think about here as someone who has just bought a Banggood facemill with 'blue nano' cutters but not tried it yet.

Meanwhile, slightly off-topic but Jason that is a beautiful piece of machining.

gary

Edited By gary.a.ayres on 09/09/2018 01:16:17

To answer my own question above -

I went to a local suppliers and found this:

It's carbon gasket material, rated at 500 degrees centigrade. I reckon that will do! The stuff is very expensive but he had an offcut which cost me a fiver. It's plain black on the other side, and surprisingly easy to work. I scribed it with dividers, cut it with scissors, drilled it, and cleaned up the edges as best I could on a small drum sander chucked in the drill press. All very easy. Here's the finished set:

Here are the top gaskets in situ:

And here's the one under the cap, viewed from below:

The gaps appear to be closed and I have no reason at this stage to think it won't do the job.

When I was cutting the bush extensions to height, I forgot to take into account the thickness of the gaskets. This turned out to be a blessing in disguise because rather than make new extensions I just skimmed the nuts down to size in the lathe, making them look slimmer and (imho) better.

gary

Progress has been slow due to hot weather (barbie season) followed by a major renovation of our living room which is currently ongoing. However, I took today off and spent some time in the workshop.

Stan Braye (on whose design this boiler is based) has little to say about he configuration of the cap, smoke stack and steam stop and safety valves, so I found myself having to figure it out myself. It was necessary to make extensions for the bushes on the top of the boiler so that the valves will sit above the cap. The first picture below shows the internal thread on one of them being tapped in round bronze bar in the lathe using a piloted spindle (which is a godsend - no more squint threads!):

I figured it would be easier to gauge the required heights for the extensions if I made the cap first. The photo below shows that the underside of the brass cap has a circular locating groove into which the top edge of the boiler fits. This was milled on my Dore Westbury Mk I using a rotary table. This is not the tidiest piece of milling in the world - a result of several issues which currently beset the mill (a situation which will be addressed in the near future...). It's not critical though as it won't be seen. You will also notice that the groove is a bit on the wide side - it's the size of the smallest endmill I currently have. Below you will see the cap (in which the hole for the smoike stack has not yet been made), the bush extensions, the cap retaining nuts (made from brass hex bar tapped M12), and the two valves:

The last photo shows a trial fit of the unfinished cap assembly. Unfortunately the two valves are out of perpendicularity with the top of the boiler. This happened either at the end plate forming stage or while silver soldering. They look squint but there is nothing I can do about it now other than put the fiery flame on it again and that isn't going to happen. It's not perfect but it shouldn't affect the functionality and will be good enough given it's my first effort. It does however mean that there is a small gap between one side of each nut and the cap. To prevent combustion gases from escaping via that route I would like to close this using some kind of soft washer or gasket which would have to be heat-resistant. Any suggestions from you good people regarding what I should use for this would be welcome. In the photo you will also see that most of the fittings are now in situ. They are sealed (hopefully) with Wellseal. Not so far away now from the second hydro test at 1.5 wp...! The picture shows the boiler in its current state sitting on the belt sanding attachment of my beloved Coronet Major woodturning lathe/all bells and whistles wood machining workstation:

gary

Edited By gary.a.ayres on 02/09/2018 00:38:51