Sealing Perfect Plastic putty? Does it need it?

[Seahawk]

I've just used Perfect Plastic putty to fill some small gaps and sink marks in plastic parts.  I am keen that this water-soluble product does not wash out again when I clean the model for painting OR interact unhelpfully with my water-based acrylic paints when I paint it (I use MIG Ammo, Vallejo and Tamiya).  

 

1.  Am I worrying unnecessarily?

2.  If not, have others found a way of sealing Perfect Plastic so it stays in place and does not interfere with paintwork?

 

Thanks in advance for your sage advice.

[Pigpen]

It's very quick and easy to use but I always get the sense it's porous and a bit fragile.

 

I brush Mr Surfacer 500 over it to fill the microspores that I imagine are there and polish it smooth with an IPA soaked cotton bud which itself is quick and easy

. I then prime with ultimate primer and have no problems.

[Rob G]

1. No. 

2. I usually airbrush or brush a quick coat of a matt medium to light grey Humbrol enamel over it when I'm finished fettling, just to protect it from further work/handling/washing. Acrylics would probably work just as well. 

[Troy Smith]

1 hour ago, Seahawk said:

I've just used Perfect Plastic putty to fill some small gaps and sink marks in plastic parts.  I am keen that this water-soluble product does not wash out again when I clean the model for painting OR interact unhelpfully with my water-based acrylic paints when I paint it (I use MIG Ammo, Vallejo and Tamiya).  

 

1.  Am I worrying unnecessarily?

2.  If not, have others found a way of sealing Perfect Plastic so it stays in place and does not interfere with paintwork?

 

Thanks in advance for your sage advice.

I got some randomly in a  job lot of paints and fillers.   I was an open tube, having read so much about it on here, I squeezed some out onto my finger.

 

My first though was some is having a laugh, this is acrylic decorators caulk

 

https://www.screwfix.com/p/no-nonsense-decorators-caulk-white-310ml/57568

"Water-based, single-component, flexible acrylic filler. Ideal for use around skirting boards, ceilings and architraves. Dries quickly and is paintable in 1-2 hours."

 

it smelled the same, felt the same.   the decorators stuff come in various grades,  can be shaped with a wet finger.   If it anything similar (and it really did feel similar) then once it's dry it's pretty durable.   

If it is the same stuff....   well....  again, we have a product being sold modellers in expensive little tubes... Not that I am in anyway way cynical....

 

I just went and had a play with the tube.   It smells and feels like decorators caulk with talc added, as it's stiffer and dryer, and felt like talc on my finger when dried off.  

 

I'd suggest it's like most other acrylic products, water soluble until cured, then not.     I'll prod about the bits I smeared in some gaps on edging of a modelling board later.

 

1 hour ago, Seahawk said:

small gaps and sink marks in plastic parts.

for this kind of stuff I'd suggest super/talc mix, or sprue goo.     

 

I'll have to experiment more with  PPP though to be fair, I'm sure it has it's uses.  

 

[Casey]

1 hour ago, Troy Smith said:

we have a product being sold modellers in expensive little tubes...

Maybe we should have a pinned section somewhere listing product alternatives, like "Masking fluid = watercolor paper masking fluid" and so on. Just an idea.

[Broadway]

10 hours ago, Troy Smith said:

My first though was some is having a laugh, this is acrylic decorators caulk

 

https://www.screwfix.com/p/no-nonsense-decorators-caulk-white-310ml/57568

"Water-based, single-component, flexible acrylic filler. Ideal for use around skirting boards, ceilings and architraves. Dries quickly and is paintable in 1-2 hours."

 

 

Once opened a tubes of caulk it has set solid the next time I have come to use, not that I really tried to keep it from setting as it's only a small % of the cost of decorating a room. I can keep PPP stored in a jar of water which so far has kept it workable.

[colin]

Problem I've found is it doesn't bind to the plastic at all, so any flexing of the model later on when handling and it cracks. 

I'll stick to using a tube of glazing putty 

[invidia]

I find it's good for small joints etc, easy to clean up and once it's primed it's fine.

  Still like to use miliput for 'bigger' jobs. 

[Seahawk]

Thanks to every who has responded so far.

 

Given half a chance, I will always use my trusty Mr Surfacer 500 (which through evaporation is now more like Mr Surfacer 250).  However there are rare occasions when I reach for PPP.  Most recently I was trying to fill some quite horribly deep shrink marks right up against the wheel hubs of a Italeri 1/72 Sd Kfz 233.  I specifically wanted something that would NOT meld with the plastic and either damage the wheel hubs or clog the tyre treads.  PPP has been just the job.  I have carved most of the excess away with a sharp modelling knife and cleaned out the recesses next to the wheel hubs with a damp cocktail stick.  Very happy with the results and I can't think of another product (except maybe decorator's acrylic caulk - thanks, @Troy Smith) that would have got me the same result.  While I had the stuff out, I tried it on a few more filling jobs and have had no problem with adhesion: it stuck well enough for me to carve with my modelling knife.

 

I've had my tube at least 5 years now, during which time I've probably used about 2 peas' worth in volume.  Whenever I use it, I put a drop or two of water down the tube nozzle and use a cocktail stick to mix it in with the filler around the nozzle hole.  I'm surprised that it tolerates me rejuvenating it in this way but impressed with these most recent results. 

 

As regards sealing, I think I'll go with @Rob G's suggestion of a thin coat of enamel (memo to self: THIN!) as I don't like the thought of using water-based paints with water-based filler.  I might experiment with @Pigpen's idea of using Mr Surfacer 500 (though if I could use it to seal PPP, I would probably have use Mr Surfacer to fill the gap in the first place).  I'm surprised no-one has mentioned the all-purpose miracle product Klear as a sealer.

 

I must admit it does stick in the craw to pay 8 times the price for the merest fraction of the quantity in the Screwfix tube.  At least it's more compact to store.  From bitter experience I am now generally very sceptical of Deluxe Materials products.  I found Strip Magic ("softens and removes paint from plastic in minutes") not only horribly expensive but functionally completely useless.

Edited October 18, 2022 by Seahawk

[Pin]

If you like Mr.Surfacer then you would also like Mr. Dissolved Putty. 

It is thicker than Mr.Surfacer 500 but still liquid, cures quickly and does not shrink once cured.

Not water based though

[Seahawk]

3 minutes ago, Pin said:

If you like Mr.Surfacer then you would also like Mr. Dissolved Putty. 

It is thicker than Mr.Surfacer 500 but still liquid, cures quickly and does not shrink once cured.

Not water based though

Thanks for the tip.  Mine did indeed cure quickly: it cured in the jar before I got round to using it!

[Pin]

4 minutes ago, Seahawk said:

Thanks for the tip.  Mine did indeed cure quickly: it cured in the jar before I got round to using it!

I periodically thin it in jar with cellulose thinner 

[Troy Smith]

28 minutes ago, Seahawk said:

 

Given half a chance, I will always use my trusty Mr Surfacer 500 (which through evaporation is now more like Mr Surfacer 250).

Re Mr Surfacer, (and I presume Mr Dissolved putty)  I thinned Mr Surfacer with Humbrol Liquid poly, which worked, and gave it quite a 'bite' on plastic (unsurprisingly)  but was kinda expensive, you can thin it easily with Isopropyl Alcohol, which I have loads of,  but it will have a bit less 'bite' then.   

Isn't as heady to use though.  I had half full jar, topped it up 3/4 with IPA, and stirred a lot.

15 minutes ago, Pin said:

I periodically thin it in jar with cellulose thinner

Which will give it quite a bite as well, but would make it pretty heady...

 

33 minutes ago, Seahawk said:

I'm surprised no-one has mentioned the all-purpose miracle product Klear as a sealer.

which is water based..... though contains ammonia I think, which is what is used to strip it from floors.       

 

Kleer is just a form of acrylic varnish.    It a hard wearing, self levelling product for floors, that by chance, (ie a later thinking modeller) realised could be very handy for modelling.   

 

As I said before, decorators caulk once cures is no longer water soluble.   A water solvent latex acrylic would not affect it, one with a hotter solvent light, but I doubt it. 

 

I'll have a look at my test bits later.

 

11 hours ago, Casey said:

Maybe we should have a pinned section somewhere listing product alternatives, like "Masking fluid = watercolor paper masking fluid" and so on. Just an idea.

Indeed.   

I do find some modellers have a touching faith that the little containers sold to them contain ingredients blessed by the modelling fairies so that are magical.....

 

One time I saw the data safety sheet for Tamiya Extra Thin....  Oh, here we go

 

I looked up the cost of Acetone and Butyl Acetate a while back on ebay, and it worked out about £20 to make 2 litres....   

 

Problem is do you want that much, and how well does it keep.       

 

The chemicals, I recall ethyl acetate and acetone, as well as 'light petrol' (eg lighter fuel)  would be commonly available in any undergraduate chemistry department as well.