[Tamar]

Posted Yesterday, 11:23 PM
Had a bit of free time so I've been sorting through my backlog of posts and pictures of the Ford GT LM.
Will try to work through them...even though other projects are already beginning to demand my attention 
So here's an other follow up on a post I promised to do but never got round to on our road to Le Mans.


Vacformed clear parts...
Some love, some hate them. Main reason racers use them is to reduce weight high up in the body, although I'd say the added flexibility they give the body is just as important. And with Ford not having that much "high" in the body, for this car the most important reason.
So its a performance part..but that does not mean you can't make them look good.
I.m.o a badly executed set of vacformed windows can totally ruin the look of a car. Unfortunately not an uncommon sight on "performance slotcars. Clear windows, no window frame, no window streamer, the Dutch have a nice word for it "Blote billen gezicht" Google it, you'll have a laugh.

Ok let us dail back the clock to somewhere mid March when Marc brought his Vacform machine to the club and used the bucks I'd perpared to pull a couple of windows and headlight lenses.
The copies were perfectly clear and had good shape definition, but...when we cut some of them and did a test fit...
...the big one piece front and rear window was too big, it would not fit inside the body.
I knew this was going to happen, because the buck I'd cast was an exact copy of the Original Scalex window.

For Vacforming the most used material is 0,2 mm thick PET sheet. During the vacforming process the sheet is drawn over the buck.
As a result of the material thickness the size of your Vacformed copy will be bigger than the original. 
There are ways to make exact sized vacformed copies... but there was just no time to make a second positive silicone cast and pour a negative buck.

In this case it wasn't such a problem as all I had to do to make the windows fit was to cut the front and rear window loose and mount them seperately in the body. 
There was still a small gap at the rear of the side windows, but at the time I could live with that.


...how to trim and detail them...
The hardest thing with cutting clear parts is to see where exactly you need to cut (even with my reading glasses) because they are..clear parts.
Depending on the quality of the vacformed part finding the edges can be difficult.
So here's a tip: use a fine steadler (waterproof) feltpen, and outline the parts before you cut them. Here's how you do that.
Flip the vacformed part so the inside is facing up. Stick the tip of the pen in one of the corners push the tip to the outside wall and gently trace the outline.
Don't worry if you make a mistake or your pen slips, it happens, even to me. Just wait a bit for the marker ink to dry and use a toothpick to (carefully) scratch away any excess ink.

Tracing the oulines before you cut the clear parts makes life a lot easier as you'll have a better guide where to cut.

To make the cut I use a pair of small curved and straight scissors to cut out the rough shape. Then its a repetition of test fitting and trimming the part to get that perfect fit.
For the fine trimming of the edges I don't use the scissors but a small sanding block/stick. Allows for much fine adjustments and gives a nice and smooth edge.

The window frames on the side and rear window were lined on the inside with the same fine steadler felt pen.
Remember how I mentioned in that earlier post how the silicone would copy anything, even the tiniest surface details like lettering on the window streamer or the tiny raised window frames?
Well these sure helped here as I could use the small edges as a guide to ink the window frames.
So a thin marker for the outlines and then I used a broader pen to fill in the whole inside. You might have to do several passes with the marker for larger areas like the air intake.
Cherry on the cake were the decals I made for the window streamer . 

 
..and how to mount them
So now you have you vacformed clear parts trimmed, detailed and ready to mount. As I mentioned before adding more flexibility to the slot body was the main reason to do them.
So for that reason I prefer to not to glue them rock solid with glue, but mount them with as much flexibility as possible. In most cases that means (double sided) tape.
For most GT's the tape will be covered by the window frame(s). In general I add full width tape to the top of the windows and just small tabs to the sides and bottom. 
When its time to firmly secure the clear parts for a race I usually add a bit of UHU Schnellfest  to the corners. It is a two component glue that remains a bit flexible and dries totally clear.
From what I've heard its similar to the GS Hypo glue some UK members like to use.

But sometimes your clear parts have very thin window frames or like the headlight lenses, none at all. Here's where I use a black  1,0 mm wide and 0,2 mm thick doubble sided tape from 3M. 
Altough tape isn't the right word, its more like mini window kit on a roll. Not surprisingly as its main use is to glue LCD screens to smartphones. 


Simply mount the tape to the edges of the headlights and press it firmly in place with the backside of a brush or a toothpick.
Once you've removed the backing paper all that is left is a thin black edge that resembles scale window kit. Then press the part in place on top of the tape.
It is the only black colored tape that is strong yet flexible enough to mount clear parts on a slotcar body. As it vulcanizes the longer it stays on the stronger the bond gets. And it looks amazing.
 
Here is a link to a Dutch webshop that sells the tape, but you should also be able to source it from your local mobile phone repair shop.

Ok that's it for now, one more backlogged post sorted...more to follow


 
With kind regards
Tamar