Lexan paint masking - liquid mask or tape? and Other paint queries...

[Mad Ax]

I've got a new Parma lexan shell that I want to do a tidy job on -

unfortunately some of the technical bits (grill etc) are really

difficult to mask using the Tamiya tape that I have.  Who has

experience using liquid mask?

Is this the stuff that paints on and dries like rubber?  Is is

necessary, when painting it on, to get the lines perfect first time -

or do I paint it on, let it dry, then trim off what I don't want with a

sharp knife (taking care not to damage the lexan)?  Do I need to

use several coats of liquid mask to get a good seal?  What sort of

brush to I apply it with, and will the brush be ruined after coating,

or can it be cleaned?

Is is possible to mask an area, spray it, then take off some of the

liquid mask to continue spraying in another colour, then take the rest

off for a 3rd colour..?  I want the main shell to be yellow, but

with some black stripes and silver or chrome grille and bumpers.

Also - re painting - does anyone know of a good UK online shop or ebay

shop that sells decals, transfers or design masks for lexan.  I'm

looking either for a mask that I can apply to the inside of the doors

so I can detail it later once the main colour is painted - I know Parma

do some but can't find a UK supplier.  Either that or those

transfer things that stick on the inside of the lexan before

painting.  Again, can find US suppliers but not UK.

Finally - is there a good lexan chrome paint for doing ultra-shiney chrome grilles and bumpers?

Thanks in advance []

[garry]

Lots of questions....

I've used liquid Mask, I think it was Parma stuff. You aplly with with a paint brush, and as you say, its like a rubber seal/coating. You can trim once dry, so get it in the right area and make it neat when dry. You can trim, paint, trim, paint no problem too. Helger imports Parma stuff, I think I got mine from Microtech, but any model shop with a Helger account can get it.

Orion, Pro-line and some people on eBay do internal decals, some look great (Pro-line do good border decals for 2-colour paint jobs).

Alclad and Spazstix do chrome for airbrushing, and Alclad, Spazstix and Fastrax do chrome in a rattle can. use the whole amount of paint, then lightly back with black.

[terry.sc]

The best liquid mask available in the UK by far is Parma Fasmask,

available to order from just about any model shop. Goes on nice and

smooth and is easy to work with. It is basically a specially formulated

latex rubber. The way to use it is to put at least 3-4 layers on the

body.  In theory you could just use one layer, but it is difficult

to peel off as the very thin layer just breaks up. Use a soft 1/2 inch

brush and spread it on evenly. Leave each layer to dry before adding

the next layer. If you only put on one layer first there is the problem

that brush marks in the mask mean it might not completely cover the

shell and secondly it ends up coming off in very small pieces and you

end up scraping it off with a fingernail. Takes a bit longer than just

putting extra layers of mask on in the first place.

I use several techniques with liquid mask and there isn't a right or

wrong way to use it. If you have window masks fit those first before

using the liquid mask, they do make it easier than trimming the liquid

mask around windows.

Just paint the mask over the inside, then draw your design on the

outside of the shell with fine tipped marker pens. If the shell has a

protective film, these marks will come off with the film, if not use

alcohol to wipe off the pen lines when finished. Then use a sharp knife

to cut out the sections of mask on the inside. I use a scalpel for

this, making sure I use a new blade for every body. The blade must be

new, that way by drawing it lightly over the film it will split the

film. If the blade is even slightly blunt you will have to push on a

little harder, which will go through the masking and scratch the body.

I find it best to cut all the design first, mainly because it is a lot

easier to see what you are doing. Once your design is cut out peel out

the sections you need to paint by peeling it back on itself, this helps

to separate the sections and stops the next section lifting. If another

section starts to lift press it back down and it will stick again.

Paint and repeat as necessary.

For stripes that need a nice straight edge as it is difficult to trim a

straight line inside a bodyshell I first use a thin lining tape to mark

the edges, then use liquid mask over the area I don't want painted. In

your case before using liquid mask I would use masking tape to mask out

around the edge of the black stripes, then use liquid mask over the

rest of the shell. This would mean you can paint the black stripes

first and don't have to worry about cutting straight edges in the mask.

For the grille and headlights there are two options, each have their

advantages and disadvantages. First option, paint the whole of the

inside with liquid mask and cut out the lights and grille. This gives a

crisp sharp edge to the mask and usually a much straighter edge than if

you just painted the mask on. This gives the best finish if you can cut

the mask out. The biggest disadvantage of doing it this way is that

usually for lights and grilles you have to trim the mask along the top

of a ridge inside the shell which makes it very hard to follow the

lines, usually in corners that make it awkward to get your knife in. Do

remember though that if you mess up the cutting you can just recoat the

mask and try again when it is dry.

The second option, which although easier tends to give more variable

results. Just paint it on the lights and grille. I do use this

technique on certain bodies, for example on Scorcher repro shells it

would be impossible to trim the mask around the headlights properly

using a knife. Use a small brush to paint out the details, again paint

on 4 coats of mask. The biggest problem is getting the edges right. A

little trick is that if you go over the lines you can wipe the mask off

straight away with a clean cloth and can give a straighter edge than

just brushing. You can practice on your shell, remember if you make a

mess of the masking you can just peel it off and start again.

For precut paint masks Parma make a good range

http://www.helgerracing.com/j7parma/j7mask...7maskpage1.html 

and like the liquid mask should be available to order from any shop

that deals with Helger Racing - if they sell Trinity or LRP products

they will have an account with Helger. The most common internal

graphics are the Team Orion ones, which can look pretty good if applied

with care.

http://www.mirageracing.com/productRange.p...ODY+subc%3ABDEC

Again should be able to be ordered just about anywhere with an account

with Mirage, which means any shop that sells HPI or Xray.

For chrome paint I have tried every one available and the best by far

has been the Fastrax Fast Finish Chrome, available from any model shop

that deals with CML which is just about every one.

http://www.modelsport.co.uk/?CallFunction=...mp;ItemID=23933

It's an aerosol, you don't need to use much as you can see the effect

building up after a couple of coats and is good enough to work without

any backing, unlike just about every other chrome. Whatever chrome

paint you use make sure you only use an acrylic paint or Parma Fascolor

to back it with, using a normal lexan paint will turn it from a

mirrored finish to a bright silver finish as it reacts with the paint

even after having been left for a while. The body below was painted

Fastrax chrome - see the aerial reflection in the chrome stripe. The

body is a Kamtec one and the surface isn't as flat as it could be,

which is why the reflection of my fingers isn't as sharp as it would be

on a better quality shell.