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Hi all,

I've been slowly building up my knowledge of more advanced modelling techniques, and all has been going well, until now...

I'm painting up a Valkyrie, and have just finished everything. FLGS gave me some awesome advice. Dipping the canopy in floor polish and letting it dry for two days allowed me to use super glue (tiny dots) when assembling (it was falling apart with PVA) with no super glue fogging on the glass. All good so far. I used some brush on asking fluid, air brushed the exterior, and it all looked awesome. Then it all started to come apart...

I used a clear lacquer to tint the interior of the cockpit. Unfortunately my first coat was too thick, and it pooled and didn't look great. Enamel thinner was brushed on, and it was gently removed. So far, so good. Second attempt to tint, again, I put too much on. again, went in with enamel thinner to remove the tint. Unfortunately this time, in frustration, I added quite a lot. And now the inside of the windows is totally fogged.

I am now utterly out of my depth here, and there are a lot of variables. Has the enamel thinner attacked the clear plastic? Has the enamel thinner reacted with the floor polish? Just how much of an idiot am I? If the fogging is just the varnish can i wipe them off, or paint strip at all, to get back to a clean surface?

Any help or experience much appreciated, although I know this is a fairly obscure little problem. At the core, what I want to assess is whether there is anything I can do te rescue the canopy, or if I need to find another one from a bitz supplier.

I use clear urethane glue(takes 12 hrs to fully cure) when gluing frames to the clear canopy. Don't forget to paint part of the frame detail on the clear canopy too.

You can try purple power or purple simply green to strip the whole thing and start over again. At worse, buy a canopy bit on ebay.

Can't find a canopy bit for love nor money right now. Since it's the one piece thats the easiest to scre wup, everyone needs more...

Yes, the thinner has probably damaged the plasticiser in the polymer for the canopy. It's boned.

There are canopy glues designed for the purpose (superglue and pva are not the best choice for it as you have learned) - as noted.

 chromedog wrote:
Yes, the thinner has probably damaged the plasticiser in the polymer for the canopy. It's boned.

There are canopy glues designed for the purpose (superglue and pva are not the best choice for it as you have learned) - as noted.

Sorry, words I don't totally understand here. The enamel thinner has attacked the actual clear plastic you mean?

Also, why are people talking about the glue I used? That has nothing to do with the problem, it's the post gluing mistakes I made here that have screwed it up...

Sand the inside if you can, then dip it in future again.

The floor polish smooths out the surface, and makes it more clear (the smooth surface reduces refraction).

 goblinzz wrote:

Sorry, words I don't totally understand here. The enamel thinner has attacked the actual clear plastic you mean?

Also, why are people talking about the glue I used? That has nothing to do with the problem, it's the post gluing mistakes I made here that have screwed it up...

Many "Plastics" are composed of essentially two parts.

Polymer and plasticiser.

Many solvents attack the plasticiser and dissolve them out or attack the polymer and dissolve chunks of it. Either way, this results in a lot of microscopic "pits" that give the appearance of "fogged" plastic. Many "Thinners" will act this way on plastics. So yes, the thinner HAS attacked the structure of the plastic, pitting it resulting in the "fogging".

While it IS possible to polish them out (in the same way you can polish out scratches in thicker acrylic (the way computer case modders do), but at the thickness of the acetate used in a canopy, you won't have a lot left of it.

As for bringing up the glue that you used ...

If you had used the right glue for the job (canopy glue), you wouldn't have had to use the finish floor polish (to prevent fogging from superglue) or the lacquer.

By the sounds of things, he'd would still have needed the lacquer no matter what glue he used - he was using that to add a colour tint to the canopy.

You can use square plastic rod (or bits of sprue if need be) to replace the canopy frame cross-pieces that are moulded as part of the clear canopy parts. Then use pieces of thin clear plastic (from blister packs is ideal) to cut out window panels and glue them in place. That's how the windows were made on the original resin Forge World model.

I admit I used PVA glue to glue the canopy parts together on my Valkyrie, and they're holding together so far. There's no need to touch the canopy area really, so it doesn't take much stress.

You can try polishing it. It depends how deeply the thinners have affected it, if it's just on the surface you can probably polish it out.

Some of the best modellers sand off the frames from canopies which makes it all foggy and terrible looking before polishing them back up. For example, this guy...

https://www.youtube.com/watch?v=WHJmxKKxsew

This guy polishes a canopy by hand...

https://www.youtube.com/watch?v=pPPhKdC84MQ

First try dipping it in floor polish. That might get rid of the fogging by itself. If not, the suggestion of sanding with very fine grade wet and dry paper, followed by floor polish dip, may do the trick though it's rather fiddly to achieve.

I believe you can dissolve an acrylic ink or tint in floor polish and dip the canopy to avoid the pooling effect. The floor polish is highly self levelling.

 Kilkrazy wrote:
First try dipping it in floor polish. That might get rid of the fogging by itself. If not, the suggestion of sanding with very fine grade wet and dry paper, followed by floor polish dip, may do the trick though it's rather fiddly to achieve.

I believe you can dissolve an acrylic ink or tint in floor polish and dip the canopy to avoid the pooling effect. The floor polish is highly self levelling.

Personally I'd try polishing (rubbing) first. Floor varnish only covers the smallest of blemishes, you have to have a pretty good surface to begin with and if it doesn't work you have given yourself the extra step of having to get it off again.

When you use floor polish to remove a scratch or mould line, you typically polish it up a bit first...

http://www.scalespot.com/onthebench/f16c/build.htm

Hey all, thanks for the responses, all the advice is much appreciated! I'm going to attempt to polish it up, as its clearly not damaged all the way through! Some high end modellers here in vancouver have suggested super fine sand paper, followed by Novus 2.

And yes, the lacquer was used separately to tint it, so other than being the source of the use of thinner had precisely zero to do with the damage. Dipping in floor polish allowed me to get a decent finish, and use super glue without fogging.


Automatically Appended Next Post:

 Kilkrazy wrote:
First try dipping it in floor polish. That might get rid of the fogging by itself. If not, the suggestion of sanding with very fine grade wet and dry paper, followed by floor polish dip, may do the trick though it's rather fiddly to achieve.

I believe you can dissolve an acrylic ink or tint in floor polish and dip the canopy to avoid the pooling effect. The floor polish is highly self levelling.

And THIS sounds like an epic suggestion!!!

 goblinzz wrote:
Hey all, thanks for the responses, all the advice is much appreciated! I'm going to attempt to polish it up, as its clearly not damaged all the way through! Some high end modellers here in vancouver have suggested super fine sand paper, followed by Novus 2.

Start with polishing and then go to sand paper, if it's only light blemishes you might get lucky and it'll just polish out straight away, if that doesn't work THEN sand it with fine paper and polish again to get rid of the scratches that were created with sanding.


Automatically Appended Next Post:

 goblinzz wrote:
Dipping in floor polish allowed me to get a decent finish, and use super glue without fogging.

Even after dipping most people prefer to play it safe and not use superglue. Even something as small as a fingerprint on the plastic will fog when superglue fumes pass over it.

AllSeeingSkink wrote:

 goblinzz wrote:
Hey all, thanks for the responses, all the advice is much appreciated! I'm going to attempt to polish it up, as its clearly not damaged all the way through! Some high end modellers here in vancouver have suggested super fine sand paper, followed by Novus 2.

Start with polishing and then go to sand paper, if it's only light blemishes you might get lucky and it'll just polish out straight away, if that doesn't work THEN sand it with fine paper and polish again to get rid of the scratches that were created with sanding.


Automatically Appended Next Post:

 goblinzz wrote:
Dipping in floor polish allowed me to get a decent finish, and use super glue without fogging.

Even after dipping most people prefer to play it safe and not use superglue. Even something as small as a fingerprint on the plastic will fog when superglue fumes pass over it.

Granted this is true, and I know it's more fiddly to use super glue, but i don't feel like driving across the city to find a specialist shop, or waiting around for a parcel. I'm being extremely careful. Once the clear plastic was washed, my fingers NEVER touch it again, it's only handled with tweezers or a clamp! Thanks for the warning though, I am still slowly working my through the more advanced techniques around this stuff.