Dog Star
Western Thunderer
Which diagram are you doing? And in what period? I ask because we have a D167 kit and the seats and tables are etch items.
regards, Graham
Fun With Rubber
- Thread starter Neil
- Start date
Which diagram are you doing? And in what period? I ask because we have a D167 kit and the seats and tables are etch items.
regards, Graham
lancer1027
Western Thunderer
Hi Graham, im doing 1970's blue/grey. My mate has a kit with the etches for the tables and chairs but they are not the ones used during the 70's. The chairs required are round, thick sort of cushion and a curved padded back rest , with the rest wood. The colour of the upholstry is a sort of burgandy. There doesnt seem to be many photos of the interior during the 70's
Rob
Rob
Dog Star
Western Thunderer
I travelled regularly between Reading and Bristol in the early 1970s. I recall such seats in the buffets. burgundy is a suitable description of the seat colour and I feel sure that I travelled in the wooden wall. Unfortunately I did not pay much attention at the time because I did not realise the historic value of the vehicle.
Neil
Western Thunderer
.... Any advice at this stage from any of you budding casters it would be most welcome ( Simon, Neil hint hint)
I'm afraid that I'm a bit of a novice Rob, but I can pass on the best advice Simon gave me, 'get on with it'. I used to teach, and I'm a firm believer that the best way of learning is by doing. I've found it to be a relatively simple process if one follows the instructions. Though Simon has a de-gassing contraption I'm not sure one is needed, the rubber seems to rid itself of bubbles naturally (or I've just been lucky) and the best casting I've taken are those where the mould has been overfilled a touch so when the top section has been plonked down the excess oozes out, the slight pressure seems to help avoid cavities. I'll be going back and making another set of moulds for the trolley using the same masters but with better venting arrangements.
Don't think I've anything else of use to say, but if you want to post pictures and words of your progress and disasters here I'll certainly chip in whit whatever wisdom I might manage to muster on the subject.
lancer1027
Western Thunderer
These are the seats im trying to make.
Has anyone any suggestions for construction or part build for easy remove from the mould.
Im trying to get as much info before i make a hash. I mean start
Rob
Has anyone any suggestions for construction or part build for easy remove from the mould.
Im trying to get as much info before i make a hash. I mean start
Rob
Neil
Western Thunderer
I was very obviously at home to captain cock up last night as my 'distractions' post should have gone here. Never mind for completeness sake here's a repeat. 
Well mixed news from the casting bench. Last week I completed the moulds for the tea van body and roof, and managed a test shot in resin.
The first cheering aspect is that the castings seem not to have any dimensional drift, body and roof fit together as well as the masters do. I'm also happy with the roof, the air bubbles that have formed are in the right places and the thin edges seem to have taken well. The body isn't as good, bubbles have been trapped in the corners, and some of the dimples in the doors have been rendered as nipples (as it were). Squinting inside the mould this seems to be the mould being at fault; when the rubber was poured it has only settled into a proportion of the dimples. I suspect that this was a result of the mould being made in a hurry to use up a miscalculation in the rubber I needed for the roof. I will be tweaking the master to include the couplings with the body, improving the venting for the resin and I'll try to ensure that the liquid rubber gets worked into the indentations.
Well mixed news from the casting bench. Last week I completed the moulds for the tea van body and roof, and managed a test shot in resin.
The first cheering aspect is that the castings seem not to have any dimensional drift, body and roof fit together as well as the masters do. I'm also happy with the roof, the air bubbles that have formed are in the right places and the thin edges seem to have taken well. The body isn't as good, bubbles have been trapped in the corners, and some of the dimples in the doors have been rendered as nipples (as it were). Squinting inside the mould this seems to be the mould being at fault; when the rubber was poured it has only settled into a proportion of the dimples. I suspect that this was a result of the mould being made in a hurry to use up a miscalculation in the rubber I needed for the roof. I will be tweaking the master to include the couplings with the body, improving the venting for the resin and I'll try to ensure that the liquid rubber gets worked into the indentations.
Neil
Western Thunderer
Nothing new, but plenty of revisions. I've altered the masters for the trolley and made new moulds. The canvas roof had runners added at each end to better vent these areas where bubbles were prone to form and the centre runner removed. The body instead of being in two parts (frame and seat) is now a single unit. The frame being quite thin tended to twist when coming out of the mould; I'd also noticed that chunkier bits tend to cast better. I beefed up the venting arrangements with this piece too with runners fixed to the underside of the coupler bodies at each end.
I hope it's obvious from the photos that the runners were added after the first half of the mould had been poured and the plasticine peeled back. The casts so far have been better for the revision. Here are the new ones on the left and the old on the right.
If there's any lesson to be learned its that vents work better at the extremities and that bigger bits cast better.
In case you're wondering what I've been doing with the tea van master, I'm part way through gently softening the multiple openings in the doors by twirling a small abrasive thingy into each depression and adding Darjeeling style couplers to the headstocks.
I hope it's obvious from the photos that the runners were added after the first half of the mould had been poured and the plasticine peeled back. The casts so far have been better for the revision. Here are the new ones on the left and the old on the right.
If there's any lesson to be learned its that vents work better at the extremities and that bigger bits cast better.
In case you're wondering what I've been doing with the tea van master, I'm part way through gently softening the multiple openings in the doors by twirling a small abrasive thingy into each depression and adding Darjeeling style couplers to the headstocks.
lancer1027
Western Thunderer
Hi Neil, very interesting.
I'm hoping to make my Gresley buffet seat master so that i can make my mould soon. Do you have any tips in the mould making part. I know this is a very early stage but i have never tried any casting before so it could all go t*ts up.
Rob
I'm hoping to make my Gresley buffet seat master so that i can make my mould soon. Do you have any tips in the mould making part. I know this is a very early stage but i have never tried any casting before so it could all go t*ts up.
Rob
Neil
Western Thunderer
Hey Neil you should get together with Simon he's busy touching up Doris and you have the rubber
'Doris' and 'rubber'; there's one to google, or not as the case may be.
Phill Dyson
Western Thunderer
Sorry Neil this has nothing to do with casting, but the seats may be of interest to Rob http://www.rmweb.co.uk/community/in...m-ian-kirk-kit-conversion/page__fromsearch__1The plan is to attempt to make some chairs for my Gresley Buffet. As im only having the one gresley buffet and there are only 24 seats i thought i would have a go at this. If however this goes ok i may move onto seats for my other coaches. Time will tell. Any advice at this stage from any of you budding casters it would be most welcome ( Simon, Neil hint hint
Rob
lancer1027
Western Thunderer
Cheers for the link Phill, Much appreciated mate.
, Much appreciated mate.
lancer1027
Western Thunderer
With the weather being crap, i decided to make a start on the masters for the Gresley Buffet seats. I will take pics later but the plan is to make 4 masters so i can ( eventually ) cast 4 seats at one go
.
I have decided to make the seat/back seperate from the legs as this is my first go at casting. If i get the desired effect i can then experiment further.
Rob
.I have decided to make the seat/back seperate from the legs as this is my first go at casting. If i get the desired effect i can then experiment further.
Rob
Neil
Western Thunderer
Well it's been a while and I'm now on the third set of moulds. Though mk2 were an improvement on mk1, I was still plagued with small air bubbles round the base of the solebars and the bottom of the canopy. Going for a belt and braces approach I added a sacrificial skirt to the bottom of the solebars and couplers and added vents at each corner (six at each end) and at two points along the side. I did this by solvent welding plastic rod in place before pouring the second half of the mould.
I attempted to do something similar with the canopy, unfortunately three of the rods broke free as I was pouring the second half of the mould and had to be fished out of the gloopy mass with tweezers. 'Oh b*gg*r' I thought, it'll be as bad as the last version if not worse. How to cut replacement vents? I know it's next to impossible to drill rubber, but I thought it should be possible to cut through. What I needed was a tubular knife or punch. I sharpened up some thin brass tube in the collect of the pendant drill, then tried punching out vents holding it in a pin chuck.
It works remarkably well. You do need something firm to cut against, I found a scrap of MDF to be just the job, and it does need broddling out every two or three punches, but it saved an otherwise useless mould. It also promises being able to take old, insufficiently ventilated moulds and render them workable.
And finally just to prove it all goes wrong, some comedy casting when the resin went off a bit too quickly.
I attempted to do something similar with the canopy, unfortunately three of the rods broke free as I was pouring the second half of the mould and had to be fished out of the gloopy mass with tweezers. 'Oh b*gg*r' I thought, it'll be as bad as the last version if not worse. How to cut replacement vents? I know it's next to impossible to drill rubber, but I thought it should be possible to cut through. What I needed was a tubular knife or punch. I sharpened up some thin brass tube in the collect of the pendant drill, then tried punching out vents holding it in a pin chuck.
It works remarkably well. You do need something firm to cut against, I found a scrap of MDF to be just the job, and it does need broddling out every two or three punches, but it saved an otherwise useless mould. It also promises being able to take old, insufficiently ventilated moulds and render them workable.
And finally just to prove it all goes wrong, some comedy casting when the resin went off a bit too quickly.
Neil
Western Thunderer
All this faffing with rubber and resin has led to another tick against the bucket list.
Now it's not the most impressive commercial venture (I had foolishly worried at one stage about demand outstripping supply) so a good job I'm not relying on this to put food on the table, but it's put a big smile on my face over the last week and for that alone it's been worth doing.
Now it's not the most impressive commercial venture (I had foolishly worried at one stage about demand outstripping supply) so a good job I'm not relying on this to put food on the table, but it's put a big smile on my face over the last week and for that alone it's been worth doing.
