I recently acquired what is probably the last new Epping/Classic stove top plate from the stock that Ellie had at Glascote.

I'm considering approaching a couple of foundries for prices on having a run cast if there's enough interest.

No idea on price yet, I know the main cost would be in the pattern making rather than the casting.

 

Just for the top plate or any other parts

5 minutes ago, noddyboater said:

I recently acquired what is probably the last new Epping/Classic stove top plate from the stock that Ellie had at Glascote.

I'm considering approaching a couple of foundries for prices on having a run cast if there's enough interest.

No idea on price yet, I know the main cost would be in the pattern making rather than the casting.

 

I saw something a while ago that said pattern making had become quite cheap as there was a new CAD system that used expanded polystyrene ( or similar) for the mold instead of wood patterns. This was in relation to casting new cylinders for a standard gauge steam loco, a bit bigger  and more complicated than an Epping top plate. ISTR a saving of £50k  was mentioned.

15 minutes ago, Tonka said:

Just for the top plate or any other parts

I'm guessing the top plate is the most sought after part. 

 

I have got a new smokebox that came with plate so I could check on that too. 

9 minutes ago, noddyboater said:

I'm guessing the top plate is the most sought after part. 

 

I have got a new smokebox that came with plate so I could check on that too. 

I could be interested in a top plate depending on the price.

I would only need a smoke box if I broke the current one on dismantling to replace top plate

With a flat  'thing'  like a top plate a good moulder may  be able to use an original as a pattern, adding a couple of bits of wood at the ends and sides, to deal with contraction.  A bit of mould fettling to blend them in and you're away.

As billh says, polystyrene vaporising patterns are a modern thing, but you need a new pattern for every item. They can be cut from big solid lumps of polystyrene or fabricated from slabs and tubes. The other new fangled thing is 3D printed vaporising patterns.  These also require a 3D CAD model for the printer to work to.  Again they need a new print for every item.

 

 

I fear the hard part will be to find a surviving Jobbing foundry that can and will work in cast iron.    I know of only a couple nowadays.Talk to your local Heritage railway and traction engine folks.  New castings are quite common in both.

There's still a few foundries around Sheffield where I'm based that advertise as casting in iron.

Whether they're small enough to take on a run of 20 or so stove tops is another thing. 

I know a chap in Wolverhampton has done parts in the past for back cabin ranges, but I found him somewhat unreliable. 

1 hour ago, noddyboater said:

There's still a few foundries around Sheffield where I'm based that advertise as casting in iron.

Whether they're small enough to take on a run of 20 or so stove tops is another thing. 

I know a chap in Wolverhampton has done parts in the past for back cabin ranges, but I found him somewhat unreliable. 

The Caldon & Uttoxeter Canals Trust may have some advice as they had a milepost cast recently, but they had the original wooden plug

I need a new smokebox if anyone can help!
 

Paul

33 minutes ago, Paul H said:

I need a new smokebox if anyone can help!
 

Paul

The chap that used to sell smokeboxes and the like on eBay is pedelee56

He doesnt seem to have much for sale at present but might be worth sending a message to.

 

There are several foundries in the west mids that could do the top plate....I have been asking around for another canal related project and was recommended this company by one of the Steam shed vols at the Severn Valley Railway.

 

Barr & Grosvenor Limited are based in Wolverhampton and provide a service to clients across the United Kingdom.
If you wish to discuss a current conservation project please contact us either by letter, email, phone or fax:
Barr & Grosvenor Ltd
Jenner Street
Wolverhampton
W.Midlands
WV2 2AE

Email: [email protected]

Phone:  01902 352390

Fax:  01902 871342

A few comments on how modern technology has made casting easier.

 

As BEngo has said, the simplest parts are those which can be moulded directly from an original. For that, there need to be no re-entrant features or internal hollows. The top plate is quite a good shape for casting that way but the smoke box isn't because you need a separate piece (core) to make it hollow.

 

There are two relevant types of casting - investment and sand. Investment casting uses a shape which is the exact shape of the thing you want to make. It can be made in wax (traditionally), polystyrene or even 3D printed PLA. You make the part, coat it in a ceramic slurry. For lower temperature metals such as brass and bronze you can use a high grade Plaster of Paris reinforced with silica but for the temperatures needed for iron the slurry needs to be a high temperature ceramic, usually a mix of silica and zirconia. You make a 'shell' on the part by repeated dipping and drying, then burn out the wax/polystyrene/PLA, cure the ceramic shell and pour in the molten metal. With sand casting, which is what is usually used for cast iron, you need a set of patterns and core boxes (to make the sand cores) which you assemble to make the reverse of the part and then pour in the iron.

 

The main advantage of investment casting is accuracy (you can get a very fine finish) and for the amateur, if you can draw the part, you can 3D print it directly which means no complex mould design. However, you do need a new one for every part you cast, which is great for one-offs but soon gets ineffective for production runs. The main advantage of sand casting is that once you have the pattern you can make a lot of parts from it at relatively low cost. However, the set of patterns can get extremely complicated, even with efficient design. We have drawn up and are now printing all the patterns and core boxes to make a Kelvin J cylinder head - it's well over 20 individual parts and more hours on CAD than I care to think about!

 

As BEngo has mentioned, shrinkage is a factor. You can build up surfaces on an original using high build paint and car body filler, plus gluing on blocks of wood where you need to add headers and risers (the bits where the metal goes in and the gas comes out). One aspect which isn't always obvious is where the gas is going to be displaced to. In sand casting, a lot of it will go through the sand which is porous whereas in investment casting you need to design in gas pathways to avoid it being trapped.

 

There are three foundries I am aware of which have been known to handle small batch casting - one in Bridport, one in Telford (which, if it still is, is the only one that has stated it will work with investment casting of iron) and one near Nottingham which I have used successfully and is where the J head pattern is destined to go.

 

Alec

 

Edited to add: there is another way to use investment casting, when you can get your hands on an original part to borrow but not keep to use as a pattern. If you apply a protective film to the part, then build it up oversize to allow for shrinkage, you can then mould it in silicone. There are expensive silicone moulding compounds, but you can also use the cheapest of bathroom silicones from Screwfix etc. There are instructions around on how to do this, but basically you take a bowl, put a layer of cheap, unscented washing up liquid (not Ecover) in the bottom and add water, then squeeze the whole tube of silicone in to it and knead it through your hands to get it thoroughly wetted. You can then mould it round the part and it cures quite fast. You can slit it on one side, peel it off (it's flexible) and then use that as a mould to fill with wax for investment casting, assuming you can find a foundry that will cast it.

Edited August 31Aug 31 by agg221

How does this compare with the Shaw Process http://www.shawprocess.co.uk/shaw.HTM ? I know Precision Products no longer exist but wondered if anyone still uses their process

12 hours ago, noddyboater said:

I recently acquired what is probably the last new Epping/Classic stove top plate from the stock that Ellie had at Glascote.

I'm considering approaching a couple of foundries for prices on having a run cast if there's enough interest.

No idea on price yet, I know the main cost would be in the pattern making rather than the casting.

 

I believe Ellie's stock came from the late Pete Dufficy of Brenmarl Engineering. Presumably he had patterns for the castings. Maybe worth finding out if they still exist and are available. @dave moore may be able to help.

 

Are you thinking of offering complete stoves?

Peter's son James on 07951156095 is now running the Epping side of Brenmarl, see the last post in this thread

 

 

I was very surprised to find  the Northfield Foundry in the middle of a housing estate in Brixham, Devon( see  also fish and chip topic). Their website

seems to offer the sort of thing for  making Epping parts. A bit different to Walsall or Wolverhampton!

Try Bridport foundry, they seem to be still going. The Bristol foundry still has its website on google etc but doesn't seem to connect - shame, that was a good place. Casting the top plate should be straightforward, just a simple sandcasting using the old plate as a pattern and if the old one is a horrible burnt and broken thing then just build it up with filler. Problem with cast iron is getting the temperature high enough, it needs to be seriously hot to actually pour the stuff.

4 minutes ago, Bee said:

Try Bridport foundry, they seem to be still going. The Bristol foundry still has its website on google etc but doesn't seem to connect - shame, that was a good place. Casting the top plate should be straightforward, just a simple sandcasting using the old plate as a pattern and if the old one is a horrible burnt and broken thing then just build it up with filler. Problem with cast iron is getting the temperature high enough, it needs to be seriously hot to actually pour the stuff.

I'm going to try the local ones first (Sheffield) but thanks for the heads up re Bridport.

Hopefully the plate I've got can be used as a pattern as it's new. 

28 minutes ago, Bee said:

 Casting the top plate should be straightforward, just a simple sandcasting using the old plate as a pattern 

Wont it end up too small if you do that 

7 minutes ago, ditchcrawler said:

Wont it end up too small if you do that 

Cast iron shrinkage is about 1%. Measure up the top and see if one 99% the size will still fit, if there is enough play in the design. If not, they'll have to make a wood pattern suitably oversize. 

1 hour ago, Jen-in-Wellies said:

Cast iron shrinkage is about 1%. Measure up the top and see if one 99% the size will still fit, if there is enough play in the design. If not, they'll have to make a wood pattern suitably oversize. 

I thought it was greater than that 

A skilled moulder  would fit the top into a drag, make up the sand to the surface and strickle it level, then beat the top to the 4 winds, so as to leave a suitably sized gap all round. Eact size of gap might get checked with a special contraction rule ( one for each metal with graduations distorted to account for contraction),  Strickle off again.    Remove the pattern item and then cover the drag with a  cope full of sand,  strickled off, then runners and risers cut  as needed.

 

Separate cope and drag, ferkle up any minor collapses, blow out loose sand, paint a coat of plumbago on both halves,  reassemble and you are ready to pour.

29 minutes ago, BEngo said:

A skilled moulder  would fit the top into a drag, make up the sand to the surface and strickle it level, then beat the top to the 4 winds, so as to leave a suitably sized gap all round. Eact size of gap might get checked with a special contraction rule ( one for each metal with graduations distorted to account for contraction),

 

A less skilled moulder might build up the surface with car body filler to the right size - as was done to make a second mounting foot from the original for a Crossley diesel which came out of Ford's foundry in Dagenham...

 

Alec

10 minutes ago, agg221 said:

 

A less skilled moulder might build up the surface with car body filler to the right size - as was done to make a second mounting foot from the original for a Crossley diesel which came out of Ford's foundry in Dagenham...

 

Alec

That's what I've always done but with something like a plate I'd just give it a bit of a wiggle in the sand - but then I measure tolerances in how much daylight I can see between the joints.

9 minutes ago, Bee said:

That's what I've always done but with something like a plate I'd just give it a bit of a wiggle in the sand - but then I measure tolerances in how much daylight I can see between the joints.

That's fair enough! I have found that I am reasonably good at reverse engineering and designing patterns based on the casting process to be applied, and can get it to a reasonable mould, but I am not a foundryman - a bit of aluminium alloy investment casting is currently my limit on the practical side.

1 hour ago, BEngo said:

A skilled moulder  would fit the top into a drag, make up the sand to the surface and strickle it level, then beat the top to the 4 winds, so as to leave a suitably sized gap all round. Eact size of gap might get checked with a special contraction rule ( one for each metal with graduations distorted to account for contraction),  Strickle off again.    Remove the pattern item and then cover the drag with a  cope full of sand,  strickled off, then runners and risers cut  as needed.

 

Separate cope and drag, ferkle up any minor collapses, blow out loose sand, paint a coat of plumbago on both halves,  reassemble and you are ready to pour.

 

You copied that out of a Harry Potter book, didn't you!