How to : - Cast your own intercoolers, many pics sorry

Thought this might be of use to some of you. For a while I have been casting my own copies of various pieces of model kit, I was recently browsing my unmades and saw the intercooler in the Tamiya R34 which i think is very nice, so I decided to cast a few copies and thought i would show you how I do it.Lots of pics so bear with me but they do help.

1 The materials
Tub of Playdoh or your equivalent (dont use plastescene it sticks), water soluble, easy cleanup,and edible if you get hungry :smile:
Car body repair fibre glass resin and hardner
Tray to hold the playdoh
rolling pin or similar
The item to be cast (will only work for detail in two dimensions but depth can be obtained (see later).

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580materials-med.jpg

2 Make your mould receiver

Put the doh in the container and roll flat, this may need to be done several times as the top surface has to be level and blemish free, no cracks air bubbles or other nasties or you will get issues later.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580rolling-med.jpg

3 Finished article

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580rolled-med.jpg

4 The Template

with a piece of sprue superglued to the back, this is needed to enable you to make your impressions.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580intercooler-med.jpg

5 Making your moulds,

This needs to be done carefully as each impresion must be done in one pass and vertically, if not your casts will come out uneven, the template must also be pulled out vertically and not rocked to get it out or again or your castings will be faulty. see later pics.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580moulding-med.jpg

If you have problems getting the original out of the doh the use a ruler or similar to hold the doh down while you pull out the original. Also dont try and get to many impressions in an area as the moulds will distort if you get them too close together.

6 Getting messy( possibly )

Mix your resin as per instructions, use or make a measuring cup graduated in whatever the ratio of resin to hardner, in my case its 3cm/1 inch to the 10cc

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580mixture-med.jpg

7 Fill the moulds

Carefully stopping just below or at the surface level.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580setting-med.jpg

Go and brew up or whatever and come back after the required setting time.

8 Remove the casts

It doesnt matter if the casts have doh on as it is water soluble and can be scrubbed off with a brush.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580taking_out-med.jpg

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580scraped_off-med.jpg

9 After washing

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580washed-med.jpg

If youve not smothed the mould or moved the original when removing it then this is what can happen, lumps and bumps or a curved cast.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580wobble-med.jpg

10 Sanding

I use a sheet of coarse wet and dry, used wet to clean up the top and botton edges and also flatten the back.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580sand_edge-med.jpg

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580sand_back-med.jpg

11 Final trim / sand

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580trimming-med.jpg

12 Paint

However you want to finish

http://files.automotiveforums.com/gallery/watermark.php?file=/500/59580paint-med.jpg

Final comments

I find this is quite a successful process, however there can be quite a high mortality rate for castings due to imperfections on the original doh mold wiggle when taking out original etc, many flaws can't be seen till the paint stage but even if you bin eight out of ten its still cheaper than buying a kit if you need a spare intercooler for a project. The only real drawback is that its only realy two dimensional but if its only to fill a hole in a front spoiler then who cares.
Hope you can follow and maybe improve my method. :sunglasse

great job. how are the results on other parts like wheels?

For using with urethane resins (the two part stuff, like Alumilite or Smooth On), Silly Putty is a great temporary mold agent. Chemically, it's silicone based, which is what is recommended for urethane molds anyway, so you won't have problems with the resin eacting with it (sticking, not setting, releasing toxic fumes, etc). Some molding agents are NOT compatible with some resins, a lesson I've learned the hard way.

great job. how are the results on other parts like wheels?

I have tried this and it works to some extent as long as you only want the front face and its not too complex a shape. if you have spare wheel backs these could be glued in place, now I have a bigger range of rims may try it again.

For the two that bothered to reply a big thank you. :smile:

For those who couldnt be bothered :disappoin

Any feedback good or bad to prove I didnt waste an hour and a half of my time might have been nice. :nono:

When you see some of the drivel that gets dozens of replies on this forum I sometimes wonder if I should bother.

Great tutorial Neil. Bring some with you at the next meeting. I've been meaning to cast my own parts for some time now. so thanks again.

Hey Verminator, less of the sarcasm please. I would have thought better of you if you'd put this thread up out of the goodness of your heart but it seems all you want is praise and lots of oooh's and aaah's.

Some people don't live with their computer stuck to their side (and constantly logged on), so you may have to be patient and wait for your acclaim!

Having said that, I do, however, appreciate this thread. Not that I need it now but you never know I might in the future, so thanks for that.

But please, if you're only posting this thread to get a round of applause then maybe you shouldn't bother in the future.

It's just a matter of time until you recieve more comments, try to be patient. :)

Nice tutorial, because the materials you are using turn out a little clear and shiny, you could also try them on headlights or other parts that should be shiny.

Thanks for the how to :)

Excelent How-to.. greatly apprecieated.
Great pics too.

well i thought it was kick a$$!

Thanks a lot for sharing this tutorial with us. THis is exelent idea and I'm sure that I will use it one of these days.

nice tut.!

perfect for the beginner modeller, although you can only do one part molds, not 2 part or multiple.

and the part in the playdoh cant have hardly anu undercut, which significantly reduces the amount of detail in the casted piece.

Great tutorial! Definatly worth a shot. :thumbsup:

cool i was going to try doing that with some parts some day a see if it would work thanks know i know it will work

hey nice tutorial! im gonna go and try this now.lots of possibillities.

could we see some more pics of the finished product? its hard to tell what the quality is like.

Interesting method Neil. Bet you got loads of complaints from the missus, that stuff stinks!

Rather than Play-doh, silicone putty (http://www.tiranti.co.uk/data/ASP/showitem.asp?ItemID=1964) is good as a 'quick fix' method of casting small parts. The benefits are that you will have a reuseable mold and consistantly good castings. You could also impress the wife further with its...err...somewhat interesting aroma :eek7:

I've been looking for an easy way to make molds...now I can do it without buying casting rubber or whatever it is...does it have to be playdoh or can it be the stuff made with kool-aid?

I've been looking for an easy way to make molds...now I can do it without buying casting rubber or whatever it is...does it have to be playdoh or can it be the stuff made with kool-aid?
Kool-aid?? Anyway I want to try this. Thanks for the tut.