'white bead' polystyrene smoothing

[ManicMan]

Probably not the best of stuff for the job but since I have plenty, I'm doing some building-like Sculpting with Polystyrene.. I think it's what is sometimes referred to as 'White Bead' polystyrene as it's the kinda standard old packing material which is like a bunch of white beads sandwiched together. Bit messy sculpting but for buildings and stuff, it's fine. Anyway.. Problem I have now is kinda the surface texturing. Using a heat gun to slightly melt the edges makes it a bit smoother and nicer for the job (yes, well ventilated).

Problem is still surface texturing.. in the past I've used a filler plaster and milliput but neither have fantastic griping properties. Wondering if anyone has any advise? Not the best stuff but cheap, easy to use stuff for light weight more bulky stuff ^_^

 

[EricF]

You could try tile grout. Generally quite fine, sticky and solid when dry and these days available in a multitude of different colours. You can get 2.5KG bags of Mapei coloured flexible grout from places like B&Q for about £10.

FWIW I'd still look to use a respirator if melting (or sanding) polystyrene (be it low or high density) myself even well ventilated. There are a fair number of half masks now on the market with replaceable filters at not crazy prices and even 3M's reusable (but not replaceable) half masks are not crazy at about £30 (fine if you are not using it lots and lots). Only one set of lungs and all that

 

[ManicMan]

yeah.. I got a bunch of ex-builders masks around here someplace (a friend of mine works for a builders company and they had to throw out a whole lot of disposable masks because a new regulation came out saying there 3M ones weren't quite high enough grade.. so he used them as packing for a parcel send to me ^_^

I don't do the stuff too much but yet, I know the kinda risks and have a habit of.... lets just say not being too concerned when it's myself.

 

[Fimm McCool]

If they weren't a high enough grade for him they might not be for you either. You need a ppf2 at least to do anything about the fumes. A lot of people didn't get that during the pandemic - not all masks are equal! Anyhoo for surface finishing I would recommend an initial coat of neat PVA to Sid future adhesion. Then you can use a mix of PVA, filler, sand and whatever else over the top to add the texture. Even one of those unnaturally even blobby spray can textures if you want since the foam is safely protected.

 

[ManicMan]

it was something to do with regulations which are a bit over kill but fair enough. But yeah, there are tons of grades depending on the 'size of the holes' in the fabric and what particles you want to keep out.. can't find the size of the particles for the flumes to know what grade masks though.. I do know that technically EPS is not only a low carbon material and one of the more 'environmentally friendly' packing materials despite companies cutting down but then.. I find alot of people don't understand how the world works.. like when they tried to claim paper straws were a good replacement for plastic ones.. yeah.. and now 'oh, study shows we were wrong'.. yeah.. no kidding.. surely you noticed alot of the problems when the were being used in the past? sigh..

anyway.. mm.. coat it in PVA first might be a good idea..