Part built Allchin 1.5 inch

Evening all,

what a lovely day, Wilton house car boot today so gramophone hunting with my dad.

yet another one added to the house!

so new day means new feelings, the stripped stud hole I put a stud from the inside, and the other three holes as they were pretty loose even when I made new 5BA bolts I tapped 4BA.

i used a 5BA nut and tapped them 4BA so everything will look the same, however I don’t have a 4BA Die so I’m going to have to make some bolts.

could I just double check what size bronze bar I will need to make these?

I will try and make them a good snug fit in the holes, the threads do look good in the holes and I have tried to take a picture so you can see the side of the strengthening plate and it’s half threads.

You will probably have to turn something down unless you can find 9/64" bronze, if turning your own 3.6mm dia is what you need.

Thanks Jason, gives me an idea what to look for now.

i will try and make them tight.

so I thought id take my mind of the fixing holes for now, and do some other parts of the build that needed finished such as the exhaust port in the cylinder block.

now I do know that I need to fit a gasket or sealant on my valve chest as these are not 100% perfect, Ive been looking at the liquid gasket type but can see lots of different opinions.

as we all know from my cylinder block cant come on and off because of the threads so id like to make sure the valve chest if air tight mainly as you know the fixings are under the cylinder and cant be got too once fitted which is a shame.

I wish I had done what a previous builder had done and that was drill from above inside the chest so you can unscrew the chest without removing the cylinder.

however I have seen some use Loctite 5910, 574, Hylomar blue...do any of you have experience with any of these sealants and think they would work?

I was thinking I could make a jig to bolt the cylinder too, so I can fit a hand pump and check for leaks from the chest without having to take it on and off the boiler.

Regards,

Derek

Sorry for yet another question, I’ve just drilled the exhaust port bigger on the cylinder and it now the same size bore as the exhaust pipe that goes into the chimney.

i struggled to get it to 6.5mm as you know I have to do everything by hand, the drawing asks for 8mm, I’m assuming I have to match that, I’m sure there is some mathematical reason why.

I will just struggle that’s all.

kind regards

Derek

Your exhaust pipe is probably a bit thick in the wall, about 16 or 14g would give enough thickness to thread but unless you are wanting the engine to do a lot of work the 6.5mm will be ok.

Oh great that’s good new Jason, I was dreading drilling bigger.

what I did do tonight was re-tap the cylinder holes 4BA I was going to do just the three but they felt so much better I thought I’d do them all.

i think they feel much better so I hope to be OK with the three missing the plate.

i have some stud coming so I will make up new bolts, if loose off the shelf I will thread my own.

did you see my question about the sealant for the valve chest, mines not perfect so need something I read loctite 5910 is good.

you can imagine I don’t want to be taking my cylinder on and off!

thanks again for your time.

A liquid gasket like that should be ok

Many thanks Jason

Hi Derek,

I have been following your build and have come across this site about another chaps efforts.

If you've seen it before, apologies - if not it may help in some way

**LINK**

Hi Essm

Yes I have seen that site, and appreciate you showing me.

its an interesting section, and I’ve actually had a quick chat with the guy who site it but he’s not done any more work on the engine I don’t think as it’s not been updated for years, but I occasionally check back just in case he updates it.

id very much like to talk to others who have built the Allchin, there must be many.

i find I learn from others far more than just reading a book, however google is very useful.

how we managed without it I don’t know, I’m only 41 but I remember not having it.

regard,

Derek

this is a huge question with limitless answers I'm sure, but how do you know if a bolt is too loose in the thread.

I mean how much wobble is expectable without causing a fixing issue, since my fiasco with the boiler holes I'm intrigued to learn what's normal and what's wrong.

if you screw in a bolt, say into the boiler shell how much slop is normal?

no rush to answer anyone, its just something I was pondering on last night.

So a week has passed since the stressful boiler issues, partly down to me over reacting because of being a perfectionist.

However kind support and proof that all's not lost has made things easier, so again thank you to all that have supported me.

I would like to get back to enjoying live steam not dreading it, now one other concern I have is the bracket that needs to be fixed to support the trunk guide, this looks to be screwed into the boiler so yet more holes!

which you can imagine I'm dreading, I think there is a strengthening pad within the shell as there is a rivet very close to that area which may have supported it during soldering.

Do you suggest I think of another way to support that bracket or risk drilling into the boiler, id imagine its far less of a concern compared to the cylinder holes but is there any other way to fix the bracket, I suspect not?

this weekend I will be making some bolts to hold the cylinder valve chest on, and have purchased some hylomar blue to seal this up.

one thing I don't want is to be removing the cylinder because of a valve chest leak!

So spent the evening making bolts to hold cylinder valve chest on from the base.

and I bolted the valve chest on after I had applied Hylomar blue, now the interesting thing will be did it seal!?

the issue I had was that my work has been hand filed, could see a tiny bit of daylight when fixing lightly clamped but pretty much perfect when fixed tight so I’m hoping any gap I may have will be fixed with the sealant.

other than fixing everything onto the boiler I’m trying to think of a way to pressure check this before fixing everything to boiler.

Will be fixing Smokebox on at the weekend and making new fire door, as the one I made doesn’t fit the boiler opening as yet again something else not correct on the boiler but I only have to make the inner plate so shouldn’t be too difficult.

has anyone had experience with Hylomar blue, and if it works on these tasks? Because anyone is thinking I’ve made a mistake I won’t be offended if you tell me, I’d rather know now.

i will update some pictures soon.

I don't think there is another way to fix the guide support, however it is not subject to boiler pressure so not so critical about how much oad the fixings have to take.

Thanks Jason, well I shall drill the fixing holes once bracket made and hope for the best.

Regards

Derek

Hi Derek,

I use hylomar and have had no problems with it but I would still be inclined to make a thin card gasket and then smear hylomar on both sides of it.

Thanks Essm

i did indeed take the valve chest off and add a paper gasket, no real way of checking for leaks until engine together but I can’t do any more to seal the valve chest than I have already.

obviously I made it hard for myself having no milling machine but if future brings one along and my interest in steam continues then great.

I'm sure I will find things much quicker and hopefully more accurate, but being my first real engine it took all my funds to get this far.

i should have really complained more about my boiler being done wrong but I was refunded the cost of the work, so I didn’t think it was fair to moan too much.

but I had to drill hornplate holes much bigger just to get any type of fixing in the centre of the stays.

meaning I have to use washers, hardly scale but I may think of an alternative in time, but for now I’m lucky to have anything.