Tips to stop priming?

[Spule 4]

OK, I test fired, the SLK1.

Good news, it runs.

Bad news, it runs on hot water, not steam.  Hot water pours from the cylinders and the smokebox, and it looses "steam" quickly.

Even when the safety pops with the water in the boiler under 1/2 full, it is not a stream of steam, it is a stream of water.

I had rinsed the boiler out with vinegar when I dis-assembled the loco, but I do not know its history in the UK before I got it.  I suspect tap water was used in the boiler and not distilled water, as it had some zinc-rot spots on the inside, but no other oil/soap/etc film.

Thanks for any ideas.

[Chris Cairns]

Garrett,

Priming occurs for a number of reasons.

1. Filling the boiler with too much water. Clearly not your problem here. I have a Bowman 265 loco and if I fill the boiler up until the water comes out of the overflow hole at the front it badly primes. By filling the boiler up to a lower level I do not get the problem (but I think this loco is suffering from reason No.3).

2. The boiler is contaminated. These boilers are put together using solder paste and then passed through a furnace. This leaves a lot of residue in the boiler which needs flushing out. What I do with the vinegar treatment is fill the boiler about 2/3rds of normal with a vinegar/water mix, then I heat the boiler up using a burner until this mix starts to boil over (safety valve removed). Let it cool down a bit then repeat a couple of times, then agitate the boiler and leave it to cool down completely and lots of flushing out with clean water. The MSS loco kit that I am building will need its boiler treated this way as there is a lot of residue inside the boiler barrel. Of course if your loco was filled with tap water in chalky England then there may still be a a lot of scale left. Usually the vinegar treatment will sort that out but I also use a scale remover on old steam engine boilers that I collect - in the UK this is sold in the supermarkets for the treatment of kettles, steam irons, coffee makers, etc. Not sure if you have the same problem Stateside.

3. Your steam take off is too low. On a standard Mamod SL/MSS the steam pipe goes up into the brass steam chest. If this pipe is not long enough (i.e. does not stick too high above the top of the boiler) you will get the water boiling over inside the steam chest and down the steam pipe. This happened to me with the MSS Saddle Tank loco and in the end I had to fit another steam pipe which went right up into the reduced steam chest nut on these locos. Unfortunately on the Bowman locos you cannot see how high your steam pipe is without removing the steam chest - but as all the boiler fittings, including the steam chest & handrail knobs, are all soft soldered this is a complex job. I'm sure this is the problem with my Bowman 265.

Chris Cairns.

[Spule 4]

Garrett,

Priming occurs for a number of reasons.

1. Filling the boiler with too much water. Clearly not your problem here. I have a Bowman 265 loco and if I fill the boiler up until the water comes out of the overflow hole at the front it badly primes. By filling the boiler up to a lower level I do not get the problem (but I think this loco is suffering from reason No.3).

2. The boiler is contaminated. These boilers are put together using solder paste and then passed through a furnace. This leaves a lot of residue in the boiler which needs flushing out. What I do with the vinegar treatment is fill the boiler about 2/3rds of normal with a vinegar/water mix, then I heat the boiler up using a burner until this mix starts to boil over (safety valve removed). Let it cool down a bit then repeat a couple of times, then agitate the boiler and leave it to cool down completely and lots of flushing out with clean water. The MSS loco kit that I am building will need its boiler treated this way as there is a lot of residue inside the boiler barrel. Of course if your loco was filled with tap water in chalky England then there may still be a a lot of scale left. Usually the vinegar treatment will sort that out but I also use a scale remover on old steam engine boilers that I collect - in the UK this is sold in the supermarkets for the treatment of kettles, steam irons, coffee makers, etc. Not sure if you have the same problem Stateside.

3. Your steam take off is too low. On a standard Mamod SL/MSS the steam pipe goes up into the brass steam chest. If this pipe is not long enough (i.e. does not stick too high above the top of the boiler) you will get the water boiling over inside the steam chest and down the steam pipe. This happened to me with the MSS Saddle Tank loco and in the end I had to fit another steam pipe which went right up into the reduced steam chest nut on these locos. Unfortunately on the Bowman locos you cannot see how high your steam pipe is without removing the steam chest - but as all the boiler fittings, including the steam chest & handrail knobs, are all soft soldered this is a complex job. I'm sure this is the problem with my Bowman 265.

Chris Cairns.

Hello Chris-

1.  I did overfill it once, that was my oops.  

2.  Yes, it has some "funk" inside.  I can get some CLR or other lime deposit remover, yes, we have hard water in the US as well!

3. Yes, I changed that too.  I had soldered the pipe in the boiler and did get it a bit short, so I slid an extension giving me about a MM or so clearance at the top of the dome, over the 1/8" line and dropped the now un-needed spring on there as a splash guard.

It is operating a bit better now, but still needs cleaned.  

And thanks to your e-mail regarding the burner, I also figured out the tubes for the wicks on the Shirley burner are about 1/4" shorter than my other burners, so I am not getting as much heat! I am going to find tubing or bullet casings to see if I can extend them.

[Chris Cairns]

And another reason after being silly earlier.

4. Adding Washing Up Liquid to your water.

I have a 50 mls syringe which I rarely use. I was running my Bowman 300 after an overhaul and as I wanted to fill the boiler to 100 mls (recommended by Gauge O Guild) I thought I'd make use of this syringe (otherwise it is 10 times with my 10 mls syringe). These syringes break down after being used with hot water so I normally put a little light oil on the rubber piston to make them free up. As I could not find my light oil, without thinking I decided to use some washing up liquid instead.

Of course when I raised steam I got some bubbling out of the safety valve and turning the driving wheels produced a lot of priming which was sweet smelling! At least it helped flush out the boiler as I've got a lump of old solder or scale stuck inside the boiler and still get some black deposits when I flush it out - not suprising really for a steam loco from the 1930s.

Chris Cairns.

[Spule 4]

Chris....

I have more heat now thanks to some shells and enlarged burner tubes.

But both the injector and safety were spitting/leaking.

So both were taken apart, and both had grey scale buildup. The ball of the safety would not even drop out until I banged on the valve to jar it loose. So I am thinking now that this is part of the (or an additional) problem.

I keep forgetting to get some CLR to clean it out every time I go to the store, so that is the next step to get the scale out.

That is all from the Foreign Office of the Ministry of Silly Mamods for today.

[Chris Cairns]

Just backs up my discussion that while the most sought after Mamod SL loco, the SL1K proved to be one of the worst build by Mamod.

Both you and Doug (dougrail) bought an SL1K from Simon Whenmouth (and both for £130), and have both been involved in a lot of work to get a working locomotive.

Interestingly I do not have a working plain SL1K in my collection either (I do have boxed unmade SL1K) . I have my troublesome SL1K ( http://gardenrails.myfreeforum.org/ftop ... -asc-0.php ) which is fitted with an 'O' ring piston upgrade kit and IP Eng dead leg lubricator and is looking somewhat abandoned in my workshop, and a Mike Chaney modified SL1K 0-4-2T which has his replacement boiler, cab mounted regulator, 'O' ring upgraded pistons, dead leg lubricator and a Merlin gas burner (edit - I did post about this loco but I'm strugging to get the missing links from Photobucket sorted out - http://gardenrails.myfreeforum.org/abou ... highlight= ). That is also sat in my workshop but needs a complete strip down and some new gaskets, etc. Not sure if it will remain an 0-4-2T as the rear pony is a poor design.

I did have an incomplete SL1K which I won on evilbay and got the missing parts for. After completing that one it was finally sold after a false start and became one half of a famous Double Fairlie Mamodification.

Chris Cairns.

[Spule 4]

Chris-

I would agree with some of the issues (the cylinder design was poor, and it seems that the frames were a bit more flexy) but I think the boiler issue was due to the water run in it while in the UK.

I guess if I go for another early Mamod, it would be an early SL1 or 2.

I was spoiled by my SL3 honestly. It ran well even in its camel dung and stock safety valve days.

Not sure on Doug's Mamod, but mine came with a bunch of Mamodifications, and at GBP 130, I got it for cheaper than what a stock one in the US would have cost.

[Chris Cairns]

Garrett,

Agreed an early SL1, SL2 or SL3 would be the best Mamods - those where the boiler back plate is riveted and the cylinders are also riveted to the chassis. These had the best quality control but of course it means drilling out lots of rivets and replacing with nuts & bolts.

I've edited my above posting. I did indeed post about the Mike Chaney SL1K 0-4-2T but I'm struggling with Photobucket again to get the missing photo links replaced.

Doug's SL1K is Swordbreaker which featured in the posting on the other Forum that you refered to about the tenders.

Hope you get the scale in the boiler sorted out OK - lots of flushing, etc.

Chris Cairns.

[Spule 4]

Clarification, I was not clear on the details of Doug's loco when he bought it from Simon, but I can say he has done a good job on it since!

Glad to see you getting photos back up.

I will say I had no problems with my transaction with Simon and would buy from him again.

[dougrail]

Hi chaps,

I seem to be haunting these forums more in a month than I have in two years!  8)

Alright then, let's see if my part of the story can provide any keys of info.

This is what I bought for £130 all in July2010



Nowadays with my experience I'd be jumping over the shop to grab an engine equipped as so, now I know what things are.

Custom Tender - made from a Mamod chassis sliced up for length
Incab regulator
3-wick meths burner
Higher pressure SV - an IPE one I suspect
Water topup valve
Brass cylinder covers
O-ring piston upgrade cylinders
Brass sidetank rails
Brass water tank filler doors.


Intriguingly, the boiler came as so:



I wonder whether this is what actually came with the loco or if a previous owner reboilered it.

What made my rebuilding experience difficult was not 'poor quality' or 'bad sale' but my own sheer inexperience. "Nova" [which became "Swordbreaker"] was never steamed in as bought condition. Originally the plan was just to replace the reverser and wheels, as the wheels had become loose on the axles.

However when I tested the SV on 'Great Star' it would not lift and the thread on the globe valve was very worn - when tested it must have been on its last legs. To replace would have been at least £37 at the time - money not worth spending when it would all be replaced by the superboiler apparatus envisaged in the long term future.

These niggles and the cost were why I elected to go all the way with the rebuild.

The engine was then stripped of all the unneeded parts as they were replaced - apparently the wheels were Loctited and saved. The reverser and cylinders were bought as a pack, and gave the new buyer no problems as far as I know - think the buyer might have been Superbiker actually!:lol:

In terms of running problems, mine have mostly been attributed to a)the DS cylinders, a plathora of probs but DS were very kind to rectify the worst, so very good of them and b)me not setting in my gas burner correctly. Once these were done ad Steve, James and Dan had looked it over, the engine has done nothing but improve - a fact I believe will continue as the springs unstiffen. And I have also learnt a hell of a lot from these chaps and said little engine.

[Chris Cairns]

If you start at the beginning of Doug's topic you will see the SL1K as purchased, and following through the postings (it is a long one) you can read up about component failures along the way (faulty safety valve, regulator thread failure, etc.).

I thought my comment about buying from Simon might be misinterpreted - although I've never bought anything from him he does come well recommended by the Garden Railway community, and very promptly replied to my e-mail enquiry about the future of the PPS Janet, etc. which lead to Roy Wood.

I was just trying to highlight the problem of buying SL1Ks which in my experience has been the worst performing Mamod SL locos.

As to the missing photos I had not realised that there are a few postings in Locomotives - Live Steam which did not make it to the Mamod sub folder - correcting those as Photobucket allows.

Chris Cairns.

[dougrail]

Speaking of which, I need to go and update my Mamod Forums monster thread with all the developments soon - new paint systems, developments in the cylinders and so forth...!

[Spule 4]

I thought my comment about buying from Simon might be misinterpreted - although I've never bought anything from him he does come well recommended by the Garden Railway community, and very promptly replied to my e-mail enquiry about the future of the PPS Janet, etc. which lead to Roy Wood.

I was just trying to highlight the problem of buying SL1Ks which in my experience has been the worst performing Mamod SL locos.

Chris Cairns.

Agreed. I just wanted to make that comment in case a newbie came along and read this later. I did want them to think of the issues reflected on the dealers.

Some say that Mamods have problems. Whatever, I vew them as opportunities for improvement.

[dougrail]

I would have to say that Simon Whenmouth has been a pleasure to deal with, even later on down the time when I was window shopping for my first 'big' loco. I believe the parts were good at the time of testing but may have been on the last legs.

Regardless, as Spule says - Mamods are there to be made one's own. That's what makes them so damn irresistable. Currently working on a pPenrhyn Mamod....*insert VP laugh here*

[Chris Cairns]

Some say that Mamods have problems. Whatever, I view them as opportunities for improvement.

as Spule says - Mamods are there to be made one's own.

Agreed.

With the exception of Garrett's SL3 we are tending to talk about 2nd or 3rd hand used Mamods so probably do not know their full history. I do have a boxed unbuilt SL1K, and a mint SL4, SL5 & SL6 but these are for my collection purposes only. So all my running Mamods came as used by someone else. My SL1 ( http://gardenrails.myfreeforum.org/about166.html ) is from the original batch before the coupling rings and track tabs were changed. It needed a new safety valve (it was missing) and the solder repaired around the steam chest fitting, then it ran great on solid fuel with no modifications.

The same cannot be said of the 3 SL1Ks I have had running. The 1st was nicknamed the "Troublesome Mamod" and whilst it does run now it has ended up with 'O' ring pistons & dead leg lubricator. The 2nd was an incomplete 45mm version, and that needed a replacement regulator/reverser valve to work properly (it now runs as half of Titan's Double Fairlie). And the 3rd one is the heavily modified Mike Chaney 0-4-2T which needs new gaskets and a lot of thought on the bunker, rear pony truck & R/C on the regulator.

At least I've now fixed my Bowman 300, with the Bowman 265 close behind, so they can be packed away and I can get on with the rest of my 101 projects, including several Mamodifications.

Chris Cairns.

[dougrail]

0-4-2 Mike Chaney Mamod? Is there a possibility of photos please Dr Cairns?

[Chris Cairns]

0-4-2 Mike Chaney Mamod? Is there a possibility of photos please Dr Cairns?

Doug scroll down to the 4th Addition in this Topic - http://gardenrails.myfreeforum.org/Late ... ut475.html

Since then I've put the bunker to one side, removed and put some new mesh on the Merlin gas burner (just need some small wire to secure this in the middle - using a tip that Tony Bird posted on the other Forum), fitted Dream Steam steel wheels (suffering the same problems others have had to get these free running) and fitted a rear drag beam so I can use a meths burner to run it. It is suffering from a lack of regular steam flow which I suspect is the cylinder gaskets breaking down, but these are on my 'To Buy' list having used up my supply. Not sure whether to stick with R/C on the regulator or turn it back into manual (current leverage for R/C is very basic and only has a limited range of movement).

Another one of my outstanding 101 projects!

Chris Cairns.

[Spule 4]

Hey, great news!!! (And no, it does not involve the Dacia Sandero)

After cleaning the boiler well and adjusting the safety, Major Hitchcock runs well. It will even drag the dead JanMod back and forth on a bit of test track, with the cylinders attached to the front axle.

No more froth, no more constant bubbling in the boiler, no more puking safety valve.

Also thanks to Chis' priming tip on the lubricator as well, things are good and oily.