I'm sure it was the stuff in the spray. My own issue with Silly Putty, and why I only ever tried it once, is that it's actually pretty expensive.

I've used Silly Putty with enamels and acrylics, Tamiya... airbrushed. No issues that way. It was likely something in the propellant.

Use it all the time with enamels and if I have to acrylics and have no issues so it must be the propellant.

I've used Silly Putty with enamls and acrylics. No problems with either.

Jim  

I didn't know Tamiya acrylic came in a can. Are you sure it wasn't a lacquer?

iSteve

I didn't know Tamiya acrylic came in a can. Are you sure it wasn't a lacquer?

Tamiya spray cans are indeed lacquer based and they're pretty hot at that.

Yep, I think Phil_H is quite right.

I've never heard/seen of Tamiya Acrylic in a can, only their lacquer based products.

I've used the Blu-Tak and U-Tack method too. When using that method, i have been left with oily residue on occasion, but normally this doesn't affect subsequent clear coats.

I think Silly Putty is slightly easier to work with, from what i've seen. I've never been able to find any here in Australia to actually try it out.

cml

I've never heard/seen of Tamiya Acrylic in a can, only their lacquer based products.

Tamiya spray paints do contain acrylic co-polymers, according to the MSDS sheets. This makes them acrylic paints. Tamiya calls them "synthetic lacquers," as the acrylics are synthetic and they contain some nitro-cellulose. This is true of their spray paint, but not their bottled acrylic paints, which are not lacquers at all (contrary to popular myth).

But that is beside the point, what reacts with the silly putty is a solvent of some sort. Whether a propellant or a paint solvent I have no idea. Tamiya spray paints have some hot solvents in them. But you can't assume an acrylic paint is strictly water-based. Most are, but not all--read the label.

I personally don't like using silly putty as a mask because it acts like a liquid over longer periods of time. Try putting a silly putty mask on a model and let it sit overnight without painting. You will find that the putty has flowed off the model somewhat.

I must be one unlucky or unskilled modeler because I have never had any luck masking with silly putty. First off i couldn't find any original silly putty of the tan color so i had to buy the colored stuff. I got yellow and glow-in-the-dark thinking that the lighter colors would be preferable to red which is the only choices  Wall Mart had.

Doing a 3 color camo i sprayed tan Tamiya acrylic for my first coat, then masked for the second color.  The silly putty imediately lost it's shape from the snake like cylinder and covered my demarcation lines. Then after I removed it , it left  ghost tracks in the tan i first painted . sigh... another do over. The darker colors where worse.  The only way I could get this to come out looking right is to over coat each color with clear as I progressed...that's spraying the model 6 times ...3 colors, 3 clear coats.  There must be a better way.

Wow, I've been using Silly Putty for years and not had any issues with it yet. And I've sprayed it multiple times with Gunze Sangyo lacquers and not had it melt, not even a little bit. Is the Tamiya stuff that much 'hotter'? 

And I've left the stuff on the model for over a week with no slippage or residue of oil or goo. 

This is what I've been using, on the right: 

I have definitely seen some great results from the use of silly putty...by others. I have never tried it. I've been using poster tack (basically same as blue-tac) for YEARS. You can get it at any office supply store...even Meijers, Walmart..probably even Krogers or VG's(in their little "office supplies" sections. I highly recommend the stuff, especially for camo.

The only trouble with it is, when it's spankin new, it's got a bit more stick to it, and can leave behind some residue, most of which can be removed by sticking more to it and peeling, repeatedly. It can also leave a mark in the paint, which goes away with clear coats. (I can't can't speak to the effects with acrylics though, I've only ever used enamels)

I've got a glob of the stuff, that I've been using since the 90's, it just gets added to/freshened up a little from time to time. 

For me, same as for Fermis.  I've been using poster putty (3M, bought cheap at Rite-Aid).   I've used it for RAF camo patterns.  It makes getting feathered edges very easy.

Update...I was just at Krogers (grocery store, for those of you not in the region)...they had it. It was Scotch brand "mounting putty". It was there with the rest of the Scotch stuff...tape and whatnot.

Get some!!!

One trick to working with it...before you apply it (especially after it's been used several times and has paint mixed in), knead it, twist it, pull it apart, repeatedly...this will soften it up a little and make it easier to work with.

"This is true of their spray paint, but not their bottled acrylic paints, which are not lacquers at all (contrary to popular myth)."

That must be why Tamiya acrylics spray better than MM Acryl. Tamiya acrylics also bite into the bare plastic and do not lift when removing masking tape unlike acryl that will scratch and lift very easily.

Jay

Hope things are going well with you since we last PMd. About silly putty loosing its form, yes it will do that if left on too long and specially if applied heavy. When I use it I flatten the putty so it's thin unless a feather line is needed then it's rolled a bit thicker to provide the desired effect but needs to be removed quickly otherwise it will do as you say. So apply it, shoot the paint and remove within a few minutes.

Hey there, ROW. Yes, indeed, Tamiya in the spray cans will make a gooey mess of Silly Putty. That's one of the drawbacks to using it. If you use an airbrush to apply the tamiya acrylics you will not have that problem. I use silly putty regularly to mask for painting. I think it's great, except for that one issue. If you're careful, you can get all the putty off even after it gets gooey, but it takes some effort. Barrett