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I hate it when I let my ignorance show but over the last month or two I keep running into the scratch building technique of "heat and smash". Now I've used this technique on kits that really annoyed me but never as a means of actually creating a new part. If somebody could bring me up to speed I appreciate it.

 

Mike

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Mike,

Heat & Smash is a simplified method of simulating a vacu-formed part. I suspect that most people who use the technique, use it to make canopy parts. If you have any old issues of the Squadron catalog, they usually show how to "Heat & Smash". Page 95 of the 2006 catalog shows the technique.

 

You start with a piece of styrene sheet. Squadron sells clear sheets for the purpose. First, you make a master. For a canopy, it can be the thick kit part that you want to replace. Mount the master solidly. Usually I fill the canopy with clay and then stick a dowel in the clay and clamp it in a vise. Then, you take a sheet of the plastic and hold it over a candle. As the material heats, it will sag slightly in the center. When it is suitably soft, pull the plastic down over the master. Use your fingers to force the plastic down over the canopy frames if necessary.

 

When the plastic is cool, cut your new part out and then finish and mount it. I will use the technique when I want to show an open canopy and the kit comes with a closed one. Simply use the "Heat & Smash" part for the rear and the kit part for the front.

 

I suppose you could use the same technique for such things as gear doors etc. HTH.

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To add a couple of fine points to Clare's technique:

 

1) wear gloves! When you pull the plastic down over the form it will "drape" over the part, but not be very tight around the bottom edges. This may be ok, but if not, you need to "pinch" the plastic in around the bottom (but BELOW the form) in order to define the bottom edges better. The plastic will still be quite warm (or HOT) so gloves will prevent you from burning your fingers as you manipulate the plastic.

 

2) Another way to do this is to use a "top board" over the plastic sheet you're heating. The top board (any stiff material; wood, thick cardboard, thick sheet plastic) will do. The idea is to cut a hole in it that is the SAME shape as your form, but just SLIGHTLY larger. The thin plastic to heat goes on the BOTTOM of this. Heat the thin plastic (it will sag away from the board) and then jam the plastic over the form and up through the hole in the board. This helps the plastic form much tighter around your master.

 

If you're going to do this very often in the future, spend the money on an old Mattell Vacuform machine. It'll solve a lot of your problems and cut your work time in half! Cheers!

 

GIL :smiley16:

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I did a search of "vacuum forming" and found a lot of sites...there are several vids on Youtube on building a homemade vacuforming setup...

 

Or, you could buy one here for a lot less, and they have lots of different sizes available: http://www.warmplastic.com/avf.html

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Go to E-bay. There are two there now with bids of $45. and $ 20. respectively. Now, they will end up going for rather more, but $1250. is ridiculous. The last time I bid for one on e-bay ( I thought I had lost mine in the last move, but gratefully, I found it), it went for c.$100. You do not need all the accessories, unless you are a toy collector. All you need is the vacforming device itself. The sheets of plastic can be cut from card stock and do not need all the little holes in the edges to work- the teeth in the edges of the clamping device will hold the plastic securely enough. I have never been able to understand why someone has not brought this device out again as a hobby tool, although I suspect it may have something to do with liability issues as the heating pan does get hot enough to burn one's self. I guess also that the market for it as a hobby tool for adults might be too small. For making small parts, it is very convenient and rather more consistent than heat and smash. Micro-mark sells a vacuforming device that permits larger parts -as much as 12" long to be made. It is based on heating plastic in an oven and using a strong source of suction such as a shop vac. It also works well, but for small parts it is unwieldy. Good luck. Nick Filippone

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I did a search of "vacuum forming" and found a lot of sites...there are several vids on Youtube on building a homemade vacuforming setup...

 

Or, you could buy one here for a lot less, and they have lots of different sizes available: http://www.warmplastic.com/avf.html

 

I am disappointed in ya, we have an excellent tutorial on a home made vacuum forming set up right there on the GMM homepage. NO cookies for you Tuesday night. :smiley24::smiley17:

 

http://www.mountainmodelers.org/main_tutorials.html

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I am disappointed in ya, we have an excellent tutorial on a home made vacuum forming set up right there on the GMM homepage. NO cookies for you Tuesday night. :smiley24::smiley17:

 

http://www.mountainmodelers.org/main_tutorials.html

 

Notice I said I did a search on vacuum forming...our own site didn't show up. Obviously, the webmaster is at fault here...

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I've seen the Mattell vacs go for anywhere from $30-$100. I paid $50 for mine almost 30 yrs ago, so I guess that would equate to $100 in new millinium $....and I'd have to say that since I've built so many "trashy" kits over the years I've gotten $1000 worth of use out of it!

 

If you do find one, make sure the pump handle is in good condition. Don't be too concerned if the vacuum presure seems a bit low. Smearing some Vaseline around the interior of the piston housing will help seal any leaks as well as improve the movement of the machanisms. As pointed out above, you don't really need any of the gadgets that originally came with the machine (although the plain mold surface platen is very useful!). I too have often wondered why someone else has never brought this simple machine back out. Best of luck!

 

GIL :smiley16:

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If you want to improve your Mattel vacu-u-from there is a refurbishing kit. It is made by Vac-U-Form. I found them on the Internet. I bought a complete refurbishing set. I haven't refurbished by Mattel vacu-u-from with it yet. I have read some reviews of it and that is what caused me to get it.

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More great info, thanks guys. Especially like the Chris and Keith hair pulling! Sort of makes everything worth while! :wub:

 

Mike, that's nothing... ;) ...you should come to one of our club meetings!!! Chris is always razzing me about being old and gray, and I'm giving him grief about anything I can find that particular day...although, for the last four days, I've been dealing with an abscessed tooth... :smiley26: ... and am probably a little more cranky than usual... :smiley9::smiley9::smiley9:

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You know the cranky and old man just opens up for so many comments. At least I have a good 24 hours almost to work on them.

Since you usually need a head start, thought I'd help you out a bit... :smiley2: :D :D

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