Filling and re-scribing trench lines - another filler experiment

[Cheshiretaurus]

Following a discussion that emerged in a Hunter build I thought I'd try an experiment.

We've all seen the trench like panel lines on Matchbox and other kits and filling them with model filler or CA gives a change of hardness to the surface that can effect getting a constant depth scribe line along or crossing it, model filler being softer and CA being harder than the plastic effecting the line etc.

In the above thread filler made from dissolving sprue in liquid cement had been used. It was then suggested that this could be used for filling panel lines. So I thought I'd try it.

Dissolved some Airfix sprue in Humbrol liquid poly overnight and created some grey goo filler.

(see Hunter build for ref to Nano tech)

Applied it to a scrap Matchbox hunter fuselage, just one section and once set sanded it flush, It does take a while to set (24hrs or more) due to volume. I also noticed it shrinks slightly during setting so a second layer might be required. Sanding was very easy though, much easier than sanding CA.

Today I've scribed some test lines onto it, One along the filled line, one across a filled line at an angle and another straight across at a right-angle. (not the most careful and accurate scribing I've ever done) one cleaned up it was given a coat of primer.

The primer covered the filled lines invisibly without the porous effect of filler showing through.

The scribed lines don't show any change in consistency as they cross the filler.

So far the results show a success.

Left pic shows the filled area on the right fuselage half only,

Right pic shows the scribed lines after a coat of primer.

Now should I start by re-scribing that Airfix Spitfire PR XIX with its trench lines?

CT

[chaddy]

In the bad old days we used carbon tetrachloride as a solvent. "Spret" was a necessary part of any plastic figure modellers armoury.

Edited January 31, 2015 by chaddy

[Cheshiretaurus]

Tetrachloride

Class A drugs for glue sniffers, I'm sure the original Airfix poly contained it.

[Tomoshenko]

Very promising results so far. The added bonus is that you can use the faint outline of the filled line as a guide.

Ah yes, first generation modelling solvents. I suspect those, and children's TV programmes like The Magic Roundabout, are much responsible for my quirks later in life.

[Cheshiretaurus]

Have some more sprue dissolving with Tamiya extra thin in another vial at the moment, see how that goes.

[AnonymousAA72]

Given the endless supply of sprue we all have, this represents a superb and reasonably cheap way of making filler. Another good point is that once it's applied, you can apply liquid cement over it to help it set and to smooth it out. It's also available in any sprue colour you have available....

[CarLos]

My favourite method is to stretch sprue and glue it on the trenches. I try to use the same diameter or even a little more than the trench width. After that I use putty (usually 3M red) and (wet) sand smooth. Works great, and it's reasonably fast. I've done that in Matchbox kits and in many vacs with overdone or not regular panels.

When I was a kid I used xylene to make the goo - modelling filler was expensive! But I never liked the results, mainly because it shrinked badly on larger spots. Well, I was rather impatient by then...

[bzn20]

CTC? Don't ever use that. There isn't a safe thing about it and we had a 10 point safety regs. on test papers. The 1st one was you had to show the Senior Medical Officer, in the Command you were in, why you wanted to use CTC instead of something that can do a similar job. Needless to say point one was as far as this was going to go.Even in the 80's there were safe disposal issues. They never had issues in the 80's except Asbesdos

[sroubos]

Interesting, looks like a good solution to this problem. How do you apply it? Using an old brush will presumably ruin it as the goo hardens? How long before the botte would dry out...?

[Cheshiretaurus]

Interesting, looks like a good solution to this problem. How do you apply it? Using an old brush will presumably ruin it as the goo hardens? How long before the botte would dry out...?

Ive been using a cocktail stick so far.

How long before it dries in the bottle. Not sure on that one. Sooner or later if its sooner I'll let you know. All depends on how good the seal is.

[Fritag]

Started one yesterday with EMA Plastic Weld. I'll see how that works.

[Anthony Kesterton]

Interesting experiment. I wonder if Mr Dissolved Putty is the same idea in a more commercial form.

[Giorgio N]

Having used this "filler" before, I can suggest another use: to clone parts. Make a mould from the original part using sylicone rubber, let it set and then pour the dissolved sprue in the mould. After some time, the plastic sets and takes all the details of the mould.

This technique has limitations, as the plastic tends to shrink in the mould and ends up filling well bottom and sides but not the top. For this reason it's impossible to make parts that must have details on all sides, but I remember having built a number of Griffon engined spitfires using noses I made with this technique from a single mould.

[geedubelyer]

This is great info. I'll be glued {~groan~} to this thread to see how everything works out.

Cheers.

[Cheshiretaurus]

Having used this "filler" before, I can suggest another use: to clone parts. Make a mould from the original part using sylicone rubber, let it set and then pour the dissolved sprue in the mould. After some time, the plastic sets and takes all the details of the mould.

This technique has limitations, as the plastic tends to shrink in the mould and ends up filling well bottom and sides but not the top. For this reason it's impossible to make parts that must have details on all sides, but I remember having built a number of Griffon engined spitfires using noses I made with this technique from a single mould.

That's got some potential for small surface fairings etc.

Any detrimental effects on the RTV?

[sinnerboy]

making a goo out of sprue & Cellulose thinners work as well

[viscount806x]

Have some more sprue dissolving with Tamiya extra thin in another vial at the moment, see how that goes.

Now there speaks a man on an unlimited budget. Tamiya cement no less, more expensive than gold isn't it? Harder to buy too...

[sinnerboy]

Now there speaks a man on an unlimited budget. Tamiya cement no less, more expensive than gold isn't it? Harder to buy too...

not any more £3.50 Hannants & other UK outlets

[Cheshiretaurus]

Now there speaks a man on an unlimited budget. Tamiya cement no less, more expensive than gold isn't it? Harder to buy too...

not any more £3.50 Hannants & other UK outlets

Maybe we got blagged with fake knock off's

CT

[sinnerboy]

good point....hold on I'll have a sniff

[Giorgio N]

That's got some potential for small surface fairings etc.

Any detrimental effects on the RTV?

Can't remember any bad effect, although this was a few years ago.

Mind, today I've abandoned this material as I can afford to buy proper resin, something that as a student was a bit too expensive for me. Also, most of my moulds back then were made using "bathroom grade" silicone sealant..

The material still has some advantages over resin: for a starter it can be glued with standard revell/humbrol glue. It's lighter than resin too, something useful for largish parts. At the same time there's one serious drawback: the "curing time" is quite long, while resin cures in a few hours.