[WWI] vacs versus injection mold

[Stephen Auslender]

I know of at least one guy who "casts" the vacs. He lays up a layer of 
"Bondo" on the inside and when it is just about hard pulls it out of the 
vac. then he lays it flat on a piece of glass to straighten it oiut as it 
finished hardening. It works great!
Yes one has to use a good sepapator.
What he ends up with is a slightly smaller airplane model, maybe 1:32.25 or 
somthing but it does not bother him. Then he builds this much sturdier model 
and has the vacuform to use again.
Which led me to the idea of doing that and then using the vac sheets to 
cover a wall of a room, It would make a very interesting, very textural and 
rather expensive wall paper.
But think of the fun when your friends come around to visit and see all 
these rare vacuform kits mounted on the wall as wall paper. A great way to 
lose friends and they faint from the shock!  Yes, the vacs would be easily 
removable for recasting - I'm not that crazy, yet.
Another way would be to cast the outside of the vacuform. You thus make a 
female mold.  The proper separator and you have another mold, in which you 
can cast yet another bondo model but this time the correct size.
Bondo is a trade name for polyester resin filled with an inert material and 
is used for repairing dents in cars. I used it a lot as my cars are usually 
purchased in a very well used condition. You can get Bondo or another trade 
name at any auto parts store. Contractors use it now to repair holes in wood 
walls of homes.
For the large models, especially with long wings, like the four engine 
bombers in 1/32 I would rather lay up a layer or two of fiberglass. They 
have very light weight fiberglass these days for use in large flying models. 
The fiberglass is much lighter and stronger and more flexible than Bondo. 
Also one can use carbon rods as inner spars to reinforce the wings.
The world of flying models if full of great things to use in the other 
modeling scenes.
Cautions, Always test your materials on scrap pieces of vacuform materials 
before risking an expensive vac.
Also be careful, these chemicals are toxic. I wear gloves when I work with 
bondo and fiberglass, I work outdoors whenever possible and when grinding or 
sanding these materials I wear an expensive face mask (not that cheapie 
thing that painters wear).
Go forth and have fun, its a great hobby.
Stephen

----- Original Message ----- 
From: "Michael Kendix" <mkendix at hotmail.com>
To: <wwi at wwi-models.org>
Sent: Tuesday, June 12, 2007 9:18 AM
Subject: [WWI] vacs versus injection mold


> >From: "Stephen Auslender" <auslend at snet.net>
>>Date: Tue, 12 Jun 2007 04:51:02 -0400
>>
>>
>>Just for the record, if I have to choose between a vacuform and a good 
>>injection molded kit I'll >take the IM every time.
>
> I understand that and I think most people I know feel the same.  The 
> trouble is for WW1 that some injection mold flying surfaces just look too 
> thick for my taste.  An example was the SPAD VII from Mac that I built. 
> Trying to thin the wings would have removed all the detail on one side and 
> that's a lot of detail to replace. With a vac, you have to make your own 
> underside detail but I have learned how to do that without too much 
> trouble.
>
>>Its just that I have no need to add every possible detail.
>
> You don't "have" to but a vac kit usually has a lot less stuff. You have 
> to make your own detail - is that what you mean?
>
>>I just like all the pretty color schemes.
>
> Definitely! I like painting the kits more than any other part of the 
> process. And the decals!
>
>>Building a vac is the closest thing to having a root canal that I know.
>
> Hmm... each to their own. I don't want to get into scratchbuilding - 
> messing around with heat sources etc. but a vac gives you the basics and 
> you add the rest using your ingenuity.
>
> I also like to collect vacs - I like the look of them on the sheet and 
> think about "The Potential". They also don't take up much room in storage.
>
> Michael
>
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