best quickest cheapest way to duplicate a part ?

I think I'd use Sculpey. Press as many impressions as you want and bake it. You'll have your mold. Norm

Thanks for replying, You suggest Sculpey for impressing the item into, then carefully remove it and bake it ?. if I dont remove it the plastic item will melt :-( Does that makes a solid mould or flexible one ?...sounds solid...if solid then how do I extract the cast item ?,,, break the mould then cast and bake another ?...but item now melted. Sorry, can you expand on this a little. Then what can I pour in to suit my needs ? Where does one get Sculpey from, any UK craft shop ? Steve

Just a suggestion here...... RTV....(room temperature vulcanizing silicon)? For mold.....it's flexible. Have you thought of melting kit sprue in liquid cement and using it for part? Might work for you. I've used melted sprue for customizing cars a lot, works great.

Mike

-- What does it mean when the flag at the Post Office is flying at half-mast? They're hiring.

Hi, RTV I think is the 'normal' route one should take, but I recall its not cheap, £17 for 1ltr, Outlets dont seem to want to sell this for small quantities, I need a thimble full !

I may still try the multipurpose silicone sealant stuff from DIY stores quickly squirted out and either spread around the part or better still the part pushed into it. Not sure though if this will set if in large quantity. I shall cut down a film canister plastic pot and squirt this into it, then push my part in. Beforehand I shall glue a stalk to its back and a cross bar to that, that crossbar rests on the pot rim stopping the part from sinking in, place it in and mark a line on the pot side level with back edge of my item, then fill up to that with silicone, ensuring there is not much below the part , so keeping the thickness of the sealant shallow to lessen any non curing chances I hope !

The idea of melting sprue in liquid cement seems worth trying , thanks v much for that. Another thought is a model filler squirted into the shape. Just bought a tube of one made by Vallejo and shall see how that performs out of the fine point end of this tube

Steve.

Do you have a local 'Hobbycraft' store?

They stock several 'mould making' options, including re-useable vinyl, RTV, etc.

The helpful staff can ususally offer advice too.

MH

Hi, Yes I rang Hobbycraft, they have a heatable mould material, (no good for my plastic original) and a latex type you paint on , let dry, paint a second layer on, and so on until you build up a mould. For fluids to then pour into the mould, the cheapest is the transparent paperweight making kit at £24.99 for 750ml. sod !

If I dont go with the melted sprue route, I wonder if any epoxy glues could be used,..I need something runny enough, araldite 5 min is too gooey by far.

Which epoxy glues would suffice ?

A friend suggests Epoxy30 slowset from the USA. I need low viscosity epoxy (i.e. flows well) , heat it slightly to increase flow, not too much though.

As an alternative to the runny sprue method, any suggestions on UK epoxies ? The part is only 5mm x 10mm x 5mm Steve

Kids Playdoh and fast setting auto body fibreglass resin

Thanks v much Ian, I shall get some, halfords 250ml £3.49 and hardener catalyst £2.29 for 40 grammes bit more sensible £££

Tried the plastic card soup but when the MEK had evaporated, the shape wasnt so full of white liquid (now solid) anymore. and with it having taken to the sides in places, it was a bit of a dogs breakfast, in order to get something pourable it takes a fair bit of MEK I found, so with the massive shrinkage happening it would take a few applications to achieve each shape. The resin should retain more of its bulk. Steve

I use the stuff sold in hobby shops in bottles, not tubes. Most of the tube stuff from the hardware stores has filler, which raises the viscosity too much. The stuff in the bottles at hobby shops is really low viscosity. Unfortunately these bigger bottles cost more. And, even epoxy, though better than polyurethane, has a limit to its shelf life.

Thanks Don, yes tinned or bottled it will be. The guy at Halfords UK auto store said the car body resin is somewhere between treacle and water, and at that price, I thinks thats the best it gets for us.

I am looking fwd to tring out gun sealant as a cheap mould.

I wonder if it will require release agent, probably. I have silicone lubricant, guess some of that should do.

Steve

Further to earlier Steve, there was an article in Scale Aircraft Modelling a few yers ago on Playdoh and car resin. I have certainly used it many times with great success. From what you seem to want it's gotta be worth a try first.

For more difficult shapes I have used some dental moulding putty I came by - not recommended as it's not cheap, but boy is it good stuff. Complex shapes benfeit from a slower setting resin and exra care to ensure full molds and no air bubbles. I have also added a quick spray of Tamiya arylic to the mixture to colour it - works fine!

Here's a link to a tutorial about casting details with playdoh & auto- resin (alas, the pictures seem to be missing, but the text steps are all there) - perhaps worth a look...

I remember a recent fine scale modeler article where-in the author used standard masking solution to build up a mold of a part he wanted to copy. Several layers of the solution were applied to the part as each one dried.

He then thinned squadron putty with testors liquid cement and stuffed it in the masking solution mold.

He was able to make 3 or 4 copies of the part.

I could poke through my back issues if you want to know the specific issue...

Thanks for the extra advice, SAM mag I shall try and find, wish I knew which edition though.

May have a word with my dentist, though as I am overdue he will haul me in !

Apparently one can decant into smaller vessels the resin from pot A and pot B, keeping separate of course, and pump out air using a gubbins that is available in stores for prolonging wine in bottles, comes with rubber bung and a plunger one way valve thingy.

One way to get air bubbles out of resin is to treat the just cast liquid to a vacuum chamber, so I reckon if one were to place the mould in a jar with hole in lid enough to take this rubber bung, a vacum could be created to encourage bubbles to rise from the master (if mould making), or risee from the casting.

Link doesnt work at all for me :-(,.....but thanks for the thought.

Steve

ian, Any idea which edition that was in, or anyone ? Sir Ray,,...pity the pics are gone, thanks all the same,

any> > Further to earlier Steve, there was an article in Scale Aircraft