Rebuilding a 2½" Gauge LBSC Green Arrow

[John Baguley]

I measured the sideways clearance on the crank axle and it came out at 0.068". The 'normal' for 2½" gauge locos is around 0.015" so a bit excessive!

To get rid of the excess I soft soldered 0.125" wide strips of 0.025" thick nickel silver (because I had some) to the faces of the horns.

That should reduce the clearance to around 0.018" which is more acceptable. You need a bit of clearance to allow the axle boxes to tilt when going over 'bumps'

John

[kipford]

John
Magic you have just given me the solution to same problem with the front axle on my Aspinall. Now why did I not think think of it, thanks.
Dave

[John Baguley]

Part 13 - Starting to paint the frames

Progress has really slowed down now with my lack of enthusiasm for painting! However, it's got to be done.

The frames and stretchers were rubbed down with emery paper to remove any traces of rust and old paint. I then went around all the countersunk holes to make sure they were deep enough to take the screw heads. I did find some that were too shallow and had to be deepened.

All the parts were then scrubbed with POR15 Metal Prep (Marine Clean) solution. This is an organic degreaser that you dilute with hot water and it's very effective at removing grease without leaving any residue that might interfere with the paint adhesion. You have to dry the steel very quickly once it's rinsed off otherwise your nice clean metal will flash rust instantly! That doesn't matter too much if you then treat the steel with POR15 Metal Prep as I do. This is basically a phosphoric acid rust treatment that leaves the steel coated with zinc phosphate and provides a good surface for the paint.

I decided to etch prime the inside of the frames and all the stretchers before assembly as it's easier to get into all the nooks and crannies around the horns. I used a rattle can of Upol Acid 8 etch primer which is the one I normally use as that was easier than getting out the airbrush and having to clean it afterwards. You do have to be careful with the rattle cans though as it's very easy to put far too much on. I do find the airbrush more controllable but a lot more time and effort to use. Before painting, I masked off the inside faces of the horns to keep the paint off the axle box faces.

The frames were reassembled using all new screws and Loctite 242 threadlocker. I then found that I was a stretcher missing. This goes at the bottom of the frames just behind the cut out for the pony truck wheels and acts as a support for the pony truck frame. I'm sure it was there when I initially dismantled the frames but it's disappeared now. It will probably turn up later when I'm looking for something else! It's only a piece of square bar so I made a new one and fitted that.

Once the frames were back together I primed the outside, the front buffer beam and the rear trailing frame.





The frames look a lot better with some paint on them. It covers up a multitude of sins!

There's a few pin holes in the front running boards that need filling and then I can move onto the top coats. I've got some rattle cans of high temperature satin black to try for the outside of the frames but the inside will be brush painted the usual red. Not sure which to do first - the inside red or the outside black.

John

[osiris09]

Looking good. Im doing a similar thing at the moment, trying to beat the weather which is quickly getting colder.

I always rattle can first. Then hand paint after. It means any spray mist doesn't find its way onto the red. The high temp paint also generally needs to be set with heat (mines around 90 degrees i think) which i do in the oven. I've not found much need for the high temp paint on the chassis though. Normally after the first steaming most paint gets hardened anyway so i just use the high temp where i need it such as the smoke box.

Keep up the good work

Jeff

[JonL]

That Upol Acid 8 is fantastic stuff.

Looks grand, nice work.

[John Baguley]

Painting Frames

I've nearly finished painting the frames. Just need to go around and touch up where the red has gone over the black in places. It won't win any competitions but looks ok from a distance!

The black is 2 coats of 'Techcote' High Temperature Satin Black and seems to give  a good finish although it goes on very heavily if you are not careful. I did get a run but fortunately it seemed to virtually disappear when it dried. The red is Phoenix Paints Buffer Beam Red and had 2 coats brushed on. It may need a third coat as I find that red doesn't seem to cover very well although the Phoenix paint seems better in that respect than the Halfords high temperature engine enamel that I've used in the past. It would have been better satin rather than gloss but that was what I had.

I've got to get some 'Doncaster' green now to do the wheels and the boiler cladding etc. will no doubt have to be repainted later on.

Progress at the moment is very slow as I lost my elder Brother Mick unexpectably last week which has hit me pretty hard. Most of my time over the next month or so will be taken up with clearing his bungalow and dealing with his estate etc. He was a prolific builder and had three complete locos, a 5" Gauge American Forney, a 5" Boxhill, a Rob Roy and three part built ones, a 2½" Gauge Fayette, a 3½" Gauge S15 and his latest, a 3½" Mona. He was busy working on the boiler for Mona when he died.

John

[timb]

Very sorry to read about your brother John.
Kindest regards

Tim

[iant]

Very sorry to hear about the loss of your brother John.

Regards,

IanT

[Deleted]

Frames are looking good John and as said privately, I give my condolences to you and family at this difficult time.

Take care sir...

Pete

[JonL]

Very sorry to hear that John. My best wishes at this difficult time.

[William A]

John, I'm an admirer from afar and as such my words probably don't carry much weight - but my thoughts are with you in this tough time.

[coniston]

Very sorry to hear of your unexpected loss, on a more cheerful note your frames do look nicely painted, well done for that.

Chris D

[John Baguley]

Thanks chaps

I think the American will have to go unfortunately. It's got a steel boiler and it's just too heavy for me to safely lug about on my own. It's a very docile loco to drive and was often used for passenger hauling at the club. One or two issues to sort out first though.

John

[John Baguley]

Sorry for the lack of updates on this project but I've just been completely tied up with sorting my Brother's stuff out etc. I now can't move in my house as it's full of boxes of stuff that still need sorting out in the future and six more locos including a running Rob Roy, Boxhill and the American plus part built S15, Mona and a Fayette. As if I haven't got enough projects of my own!

The garden has been completely neglected over the last couple of months so that is like a jungle and needs sorting out as well.

Anyway, I'm now back on the Green Arrow but it's only painting so not much of interest to show yet. I'm painting the driving wheels at the moment which is rather fiddly (and boring!) as I'm brush painting them. I've used Upol etch primer as usual and the Doncaster Green doesn't seem to cover very well at all on top of that so they are going to need several coats I think. I would probably have been better spraying the wheels but the masking off would have been a bit tedious so went the brush route instead. To be fair, you are supposed to use a dark grey primer under the top coat to get the true colour and the Upol is only a very light grey. As long as it looks ok when it's done I'll be happy. I'm not fussed about it being exactly the right colour.

One other job I have done is repair the front pony truck frame which had one of the guard irons broken off. I don't know how that happened as they are part of the frames which are made from 3/32" steel! I just silver soldered a piece of steel in place and then filed it to shape. These frames are now painted satin black as well.

More soon hopefully

John

[John Baguley]

Just a quick update to show that the project is still alive! I haven't had a lot of motivation over the last months so progress has been very slow.

The wheels are now painted (thank goodness!) and ready to go back in the frames. The inside cylinder is also painted and ready to fit. I'm working on painting the outside cylinders and then they can be fitted as well. Once they are fitted I can fit all the motion and have a running chassis again

One job I did want to do before I painted the outside cylinders was to make some nice front cylinder covers as fitted to the full size loco. They were simply machined from a piece of solid aluminium bar that was lying around. This was the first time that I used the new DRO on the ML7 in earnest and it did make things a lot easier.

The covers are too deep really but I didn't want to thin down the cylinder end covers any more. I could have replaced the hex head bolts with countersunk ones I suppose but that's more work that I don't want. I think they look ok anyway.

More updates soon hopefully.

John

[John Baguley]

Well, some progress with reassembly but not as much as I would have liked. Unfortunately, it was a case of two steps forward and one step back!

I refitted all the driving wheels, fitted the coupling rods and fitted the outside cylinders. The outside cylinders have to be fitted before the inside cylinder otherwise it's impossible to get to the top screws that hold the outside cylinders.

However, things did not go according to plan. After fitting the cylinders and coupling rods I found that the front bosses of the coupling rods hit the inside of the crossheads! I puzzled over this for ages. How could that be? I had run the chassis on air before disassembling it for painting. After a while it dawned on me - when I tested it on air I only had the centre driving wheels installed and no coupling rods so the problem did not show itself. It obviously wasn't a problem with the old cylinders but now the new cylinders had been machined to the drawings the problem had appeared.

Fortunately, the problem was fairly easy to resolve. I thinned the front coupling rod bosses by about 0.015" and milled a 0.025" clearance on the inside of the crossheads.

Problems solved, or so I thought. I then found that the LH piston was hitting the front cylinder cover. What! That hadn't shown itself when running on air. At first I thought that the piston had unscrewed itself from the end of the piston rod so I removed the front cover of the cylinder. That was when I found that I had got the pistons mixed up when I put the cylinders together again. I had fitted the RH piston to the LH cylinder and vice versa. Doh! The rods were obviously slightly different lengths and the LH rod was now too long.

The original plan was to dismantle both cylinders again and swap the two pistons over to their correct cylinders but removing the RH front cylinder cover showed that the piston rod for that cylinder was near enough the right length. So, I just took the offending LH piston and rod out and shortened the rod by about 0.030" to give clearance at Front Dead Centre. Problem solved.

Hopefully, I can carry on now and assemble the rest of the motion work without any more brain fades!

John

[John Baguley]

More reassembly of the frames completed. All the valve gear is installed again along with the inside connecting rod and the rams and eccentrics for the twin axle pumps.

The clearance problems with the front coupling rod bosses reared their ugly head again when I refitted the motion brackets. The bosses fouled the inside of the brackets so I had to mill a clearance on the inside edges.

The next jobs are to paint and refit the reverser stand, fit the front pony truck and the rear trailing wheels, retime the valves, fit the outside valve chest covers and then the steam and exhaust manifolds. Then another air test.

I shall be glad when the chassis is complete and then I can move on to the boiler. I did test this to 160psi before I decided to buy the loco and found several leaking stays inside the firebox and a leak on the front tubeplate. I'm guessing that the flange for the steam pipe from the regulator is just screwed straight into the tubeplate without a bush so hopefully it's just the threads that are leaking. The firebox stays are threaded and nutted and caulked with soft solder as was traditional when this loco was built so those leaks should be easy enough to fix. Fingers crossed!

John

[John Baguley]

The chassis is back together and running on air again. A major milestone in the rebuild!

There's still a few jobs to do such as refit the cylinder cladding, although I doubt if the original cladding will fit the new cylinders so will probably have to be replaced. I should have done this before painting the cylinders and refitting them but didn't think at the time. The buffer stocks are painted and ready to fit. I've painted them red as they were done originally but I notice from a photo of Green Arrow taken back in 2008 that they were painted black. I'll probably leave them red as I'm not bothered about it being an exact replica of the full size. I just want to get it running!

Running on air didn't go according to plan. I had to faff around resetting the middle cylinder valve again and it's a right pain with not being able to see it. All you can do is set it by trial and error - adjust it one way or the other until it runs properly! I thought that I had got it spot on until I tried running in reverse and it flatly refused. Playing with the valve setting again I got it to run equally well in forward and reverse as before. I could have set up some sort of outside indicator I suppose as has been described by other people but the trial and error method worked eventually.

The outside valves were set accurately by determining top and bottom dead centres by tramming and the valve opening at dead centres adjusted until equal using feeler gauges. There are plenty of videos on Youtube regarding finding top and bottom dead centres including a good one by FredV who is on this board. Using the feeler gauges I found that the lead for the valves to be around 0.007". I had deliberately reduced it when I calculated the length of the new valves. The LBSC valve gear gives something like 0.020" as drawn but I'm not a fan of large leads now.

I was annoyed when I found oil bubbling out from where the RH cylinder bolts to the frames so I guessed that there was a leak in the valve chest to cylinder block joint which hadn't manifested itself before. The joints had originally been sealed with Loctite 575 flange sealant and I hadn't disturbed this joint when I stripped the cylinders and painted them. The sealer must have cracked during that process or the leak had been there from the beginning and I hadn't noticed it. It wasn't a big job to remove the valve chest and reseal it but it was a job I could have done without.

I wouldn't recommend using the 575 for this job and I won't use it again. The problem is that it sets pretty hard as soon as the joint is put together and if you are not quick at getting the bolts in and tightening them down then the joint doesn't seat properly and you may get a gap, which is probably what happened here.

The motion was quite stiff after putting it all back together but it's freed up nicely after running for a bit and it runs on about 10psi now and notches up well.

Onto the boiler now and see what horrors await me there!

John

[John Baguley]

The Boiler at last!

I decided to take the plunge today and strip the boiler for inspection and repair.

First job was to remove the cladding starting with the prototypical pear shaped dome cover. That had a single screw to hold it to the inner dome so I removed that. The dome refused to come off. I thought it was just stuck with paint but scratching the paint off around the joint to the cladding showed that it was actually soft soldered on! A bit of heat sorted that out and it came off. It's a good job I intended to repaint the cladding as the paint was now well and truly scorched!

Then it turned out that the cladding, which is made of thin steel, was also soldered to the firebox around the throatplate and the backhead to hold it in place. More heat and more burning paint. I did this in the kitchen and you can still smell it!

The 'insulation' under the cladding was just some thin cardboard from the box for an unmentionable product that was available when the boiler was built. I shall probably replace the cladding with brass as the steel was already very rusty in places.

I managed to strip all the backhead fittings off without shearing anything off and was pleasantly surprised to see that everything on the backhead had bushes rather than being screwed straight into the copper. I wasn't expecting that.

I think the blower valve is screwed directly into the backhead and then either silver soldered or, more likely, soft soldered so I'm not going to disturb that. The steam turret was held on with two screws and then soft soldered to seal the joint but a bit od heat enabled that to be removed.

The superheater header was held by three steel screws (why do people use ordinary steel screws!) but fortunately they were not rusted too badly and came out without shearing off.

There is a large amount of soft solder on the front tubeplate but the tubes etc. are actually silver soldered. I guess that there was a leak and someone went a bit OTT with the soft solder to seal it. I'll clean it all off to see what it's like underneath.

The inner dome was again held with countersink head rusty steel screws. I managed to get two of them out after applying some heat but the rest refused to budge. I had to drill the heads off them and could then remove the dome by gentle prising. I manged to remove all the stubs by gripping them with some surgical forceps and gently rocking them back and forth until they broke free.

The regulator is the sliding block type as per the drawings. I don't know how it was fitted or how you would ever remove it if you needed to. It would be a right job. There's some more soft solder at the front of the dome bush but I realised that it was to seal a fixing screw that holds the regulator block to the boiler barrel.

The boiler has the LBSC combustion chamber and I'm hoping that there are no leaks in it. I don't think it leaked when I tested the boiler before so fingers crossed.

All in all, the boiler looks quite well made and I don't think it will take much to get it pressure tight. As mentioned earlier, there were a couple of stays leaking in the firebox and a leak on the front tubeplate that was probably the superheater header joint.

The boiler does show signs of being fired at some point judging by the black on the firebox crown and inside the combustion chamber although the grate looks clean.

Next job is to bung up all the holes and give it another pressure test to see where the leaks are.

John

[Deleted]

That's looking good John, I think someone was looking down smiling on you when getting those rusty steel screws out. Fingers crossed the rest of the testing goes just as well.

Good luck...

Pete