Acetone and polystyrene

[jamstraz]

I'm getting conflicting information. Right now I'm using Tamiya putty for my gaps but some videos I've watched have used bondo and other things and they clean it up with acetone nail polish.....Which confuses me. Acetone + Polystyrene = MELT. How come some use it with no issues?

 

[robn1]

Nail polish remover isn't straight acetone, it's diluted.

 

[jamstraz]

Nail polish remover isn't straight acetone, it's diluted.

While true, I might have a bad interpretation. Rum on it's own will get you drunk. Rum and Coke still gets you drunk, just more slowly and more needed. But the effect is the same. Acetone is diluted but, wouldn't it still cause some damage?

 

[robn1]

Prolonged use could cause damage sure, but it will attack paint and filler before it affects the plastic. As with anything else, test it on the kit sprue first to see what it will do.

Just don't use straight acetone from the hardware store.

 

[The 48th Ronin]

How bad are your gaps? If they're not too wide, Perfect Plastic Putty is... well, perfect. You can smooth it with water and it sands beautifully. Highly recommended.

 

[Sluis Van Shipyards]

I have noticed that if you putty and wipe with nail polish remover you're usually good. If you repeatedly do it without letting it dry between it will start damaging the plastic. So wipe it down and wait a few minutes before trying again. Also try the remover on a piece of sprue first if you can, to see how it affects it, because different plastics will respond differently.

 

[jamstraz]

How bad are your gaps? If they're not too wide, Perfect Plastic Putty is... well, perfect. You can smooth it with water and it sands beautifully. Highly recommended.

View attachment 1291233

Gaps aren't really too bad, maybe a max of 1mm unless it's a seam. I have been using Tamiya White Putty for it and it does the job but eventually I will run out and was looking for a cheaper alternative as well, hence how I saw the nail polish thing.

 

[jamstraz]

I have noticed that if you putty and wipe with nail polish remover you're usually good. If you repeatedly do it without letting it dry between it will start damaging the plastic. So wipe it down and wait a few minutes before trying again. Also try the remover on a piece of sprue first if you can, to see how it affects it, because different plastics will respond differently.

Good advice, I have saved most of my sprue for accidental hole filler. Heat it up, pull it apart into a long thing strand, jam it in, thin cement the inside, cut the end inside flush and outside too, and sand it down. Hole filled. Redrill in about an hour or less.

 

[ZOMBIEREPELLENT]

Do yourself a favor, and stop using solvent based putties. They're not stable, they shrink over time, take forever to cure, and crack when scribing into them.

I use superglue almost exclusively. If I need to thicken it, I use the powder from acrylic nails, and mix that into it until I get the desired consistency. You can still use kicker on it. Scribes and tools cleanly, and bonds incredibly well. I've even used this method for filling in missing panels in wings, because the kit supplied ones don't fit well. Best of all, it's available everywhere, and can be worked in minutes instead of hours.

 

[jamstraz]

Do yourself a favor, and stop using solvent based putties. They're not stable, they shrink over time, take forever to cure, and crack when scribing into them.

I use superglue almost exclusively. If I need to thicken it, I use the powder from acrylic nails, and mix that into it until I get the desired consistency. You can still use kicker on it. Scribes and tools cleanly, and bonds incredibly well. I've even used this method for filling in missing panels in wings, because the kit supplied ones don't fit well. Best of all, it's available everywhere, and can be worked in minutes instead of hours.

I have ca and I have nail powder.....but I really have zero idea of how to work it to make the stuff. I can try it on my Enterprise when I have the saucer together and lights ready I suppose. It's too late for my rom BoP

 

[modelcitizen]

he wrote in his post how to make it...mix it with the powder. and he was writing about seam filler.

 

[jamstraz]

Everytime I use CA...it becomes a mess. I get my fingers stuck, finger prints on things.

 

[modelcitizen]

are they thumbprints?

 

[patrickivan]

View attachment 1296301

What a conundrum when one states that you're

sitting around with your thumb up your ass

 

[ZOMBIEREPELLENT]

Everytime I use CA...it becomes a mess. I get my fingers stuck, finger prints on things.

Well there's your problem, all you have to do, is not do that.

Get yourself some de-bonder. It's a real thing that I wish I knew about decades ago. There's at least four instances that I wouldn't have had to explain away, if I only had some.

 

[jamstraz]

Well there's your problem, all you have to do, is not do that.

Get yourself some de-bonder. It's a real thing that I wish I knew about decades ago. There's at least four instances that I wouldn't have had to explain away, if I only had some.

De-bonder? Only thing I know that debonds CA is acetone.

 

[ZOMBIEREPELLENT]

De-bonder? Only thing I know that debonds CA is acetone.

De-bonder also works, and its non toxic.

Actually, it might still be toxic, just not as toxic and it doesn't melt plastic. So probably don't drink it.

 

[modelcitizen]

and although superglue is mostly non toxic, don't drink it either.

 

[star-art]

I agree in principle about the potential misuse of solvent-based putty. A master of scratchbuilding once told me to use 2-part polyester putty for large gaps (anything 1/8-inch or bigger). Once that's sanded down, he used lacquer-based air-dry "touch-up" putty (commonly used in auto bodywork) only as a surface prep to smooth things like scratches. In general, he would not lay this on any thicker than 1/16 inch. It *does* shrink and it *can* crack and that can be very annoying. But, if you know when and how to use it, it can work just fine.

A lot of people use CA very effectively for this sort of thing. I'm a fan of CA, though I don't use it this way. It may not be totally stable over the extreme long-run, either. But, it's often a very quick way to get the job done.

 

[Sluis Van Shipyards]

I've tried debonder and never got it to work properly. Acetone has always worked.

I agree in principle about the potential misuse of solvent-based putty. A master of scratchbuilding once told me to use 2-part polyester putty for large gaps (anything 1/8-inch or bigger). Once that's sanded down, he used lacquer-based air-dry "touch-up" putty (commonly used in auto bodywork) only as a surface prep to smooth things like scratches. In general, he would not lay this on any thicker than 1/16 inch. It *does* shrink and it *can* crack and that can be very annoying. But, if you know when and how to use it, it can work just fine.

A lot of people use CA very effectively for this sort of thing. I'm a fan of CA, though I don't use it this way. It may not be totally stable over the extreme long-run, either. But, it's often a very quick way to get the job done.

I love Bondo Spot Glazing Putty. Best stuff ever! I only used it for small shallow areas though.