Securing Sand on MDF

[Maschinenpriester]

Hello Brothers!

 

I am currently working on a mobile, foldable Gaming board, which also will have a mostly sanded surface, with some bits and hardfoam. I attatched the sand as I normally do on my bases with som PVA Glue mixed with water. for some reason the Sand does not stick as good. So single sand pieces fall of all the time. Don't know if that would be a Problem when I paint it. I am fearing more sand will come of when i am at drybrusching or even when i am Playing on it or while transport. Any Ideas what I could do to solve that problem?

Maybe spraying it with a mix of PVA glue and water?

Of Course varnish could work afterwards. But i think it'll mess up the look of the board's paintjob a bit.

 

I am also documenting the Process a bit. So ill do a little tutorial or tour on it when i am finished.

 

It'll take me some time though. ^^

Edited January 11, 2018 by Maschinenpriester

[Marshal van Trapp]

Maybe try roughing up the surface first? Model bases are not totally flat so maybe a non-smooth surface would adhere better?

Failing that try something like gorilla glue, or really any super strong glue

[Mileposter]

I did a sandtop texture to my battleplates, and I found it works quite well if you go over it a second time with a pvc glue (I don't water mine down) once your first pass has settled and dried. This got it to hold in place well.

 

That said, it never will seem too sturdy a hold until your paint seals it in.

[Maschinenpriester]

Yeah Allready had that thougt. Totally will do that on the secon half of the board. Unfortunately 50% of sanding is allready done and then i recognized that problem. ^^

But its not that whole sections of sands fall of. Just little pieces. But If painted it would leave a white spot I think.

 

I guess I'll also not water down my glue in addition. ^^

But wouldn't a second layer of unwatered PVA glue kida destroy some detail?

Edited January 11, 2018 by Maschinenpriester

[Arkhanist]

Blob on extras patches of sand with neat pva in any bare spots, then you could spray a decent primer over the top to hold it down before painting it further - the spray should be less damaging than drybrushing and you'll be able to paint over it fine. If you want an alternative to PVA, matt medium can be bought cheap in bulk - and is basically transparent acrylic paint, so holds better and thins well with water - it's a common trick for railway modelling flock.

 

If you want to keep the natural sand colour, an acrylic or polyurethane varnish spray would work like a primer to hold it down without changing the colour much, and can be painted over afterwards normally with a drybrush etc.

Edited January 11, 2018 by Arkhanist

[apologist]

I used wood glue for the sand on my Chanterwick Purefinder board [+noosphericinloadlink embedded+]. I slightly diluted the wood glue and applied it, then added the sand on top. I then further watered down the wood glue and gently poured it over the top to seal it in securely. The result is very sturdy – you can see it here in between the cobbles, and in larger channels on the right-hand side of the image:

 

Edited January 12, 2018 by Apologist

[Subtle Discord]

I'm still a strong advocate for using Acrylic Adhesive to glue my basing materials down. I've had a bottle of Perfect Paper Adhesive for decades and it is hands down the best waterbased adhesive I've found for this kind of task. It's intended for bookbinding and paper collage art, but I swear by it for basing. I haven't used it at a table scale (I will at some point in the somewhat near future), but I'll still stand by how it'll perform. It is a little more expensive than standard glue but it waters down very well for extra coverage, and a bottle for just basing miniatures will last for a looong time; I'm only on my second.

 

By design, it's not very sticky when you apply it so it spreads/paints on very easy, and it's very easy to wipe away from lips and edges while it's wet to help keep things clean. Since it's acrylic, once it's dry it's totally waterproof so it'll never soften if/when you paint it, even if you use a heavy wash. It'll dry very tough and stick very well, even on unprimed plastic, but it's still flexible and totally clear. It also shrinks nicely as it dries and tightens to the surface so it won't mute the texture. It will hold sand very fast, but it's really good at holding the basing 'sand' I use that's a milled product (probably nutshells), because it's a little more porous and the adhesive soaks into the 'sand', drying into a very tough crust. I can scratch at it with my fingernail and hardly remove any of the grains.

 

Edit: Grammar is good.

Edited January 12, 2018 by Subtle Discord

[D3L]

after your sand layer (adhered with PVA to the board), add another layer of 58% PVA, 40% Water, 2% washing up liquid, wait for that to dry, and it'll set rock hard and be painting proof 

[Major_Gilbear]

I moved away from glueing sand or flock to very big areas a while back, partly for these reasons.

 

As I appreciate that you're already well on with it, some thoughts/suggestions follow:

 

- I would consider lightly brushing the surface with a dustpan and brush to remove any poorly-adhered sand first.

 

- Next, I would apply some more thinned PVA in any obvious bald/thin areas, and re-apply more sand. Don't thin the PVA too much, and make sure you mix it really well. I suspect that the reason some areas haven't stuck well is likely because the water-PVA mix wasn't thorough enough, or applied evenly enough.

 

- Then seal the sand surface. As others have said, half/half water PVA works well.

 

- Paint. I would thin the first layer of paint so it's quite watery, and add a dab of PVA to it too. This will soak in and form a second seal. Subsequent layers of paint can be normal paint.

 

 

What I might suggest as an alternative in future is textured masonry paint. This is flexible, coloured, and is textured.

 

For these sorts of applications, I use Sandtex. I chose one with a fine-to-medium texture. I brush this on to get an even coverage, and then go back and stipple with an old bush to ensure a nice even finish before it dries. Doing two coats gives you a nice textured finish that you can then paint over further if you want. I also use it on scenery for any plastered/adobe/concrete textures. You do need to stir the tub both well and regularly to ensure that the sand in it doesn't all sink to the bottom, but it's otherwise very easy to use and the brushes can be washed out in water.

[Kinstryfe]

Mostly what others have said, but when I'm basing with sand or gravel:

PVA Glue and add the material.

Let dry.

Mix up a slurry of PVA, water, and Black2.0 paint. The pigment is plentiful enough that I use this to seal the material and apply a base coat at once.

Let dry.

Paint as you'd like.

[asianavatar]

Have you considered trying Krylon Textured spray paint as another layer. Spraying it over the sand might secure it down

[Major_Gilbear]

I've used texture spray paint quite a bit for my boards. Whilst the paints have many good features, they aren't the sort that would help to secure sand onto a surface.

[Maschinenpriester]

Thanks for all the useful Ideas and Hints! May the emperor be with you!

 

I Think I was too greedy with PVA and thinned it down too much.

 

I solved the problem by applying loads of 50/50 Water/PVA glue and some acrylic paint and washing up liquid. I just made one mistake.

It I gues I was too exited and put tooo much on the Table. Now the MDF soaked and started warping.

 

But lucily it built a sturdy frame around it in advance, so it just looks like a hill and a sort of crater, which gives the board a more natural appeal.

[Major_Gilbear]

Now the MDF soaked and started warping.

 

If you put some watery PVA on the other side of the board, it can help to pull it back flat. Even if it douesn't get it completely flat, it should be better.

 

In industrial terms, when applying something to other side of a sheet that causes it to warp, applying the same/similar to the other side is called "balancing". You often see this with laminated timber products.

[Maschinenpriester]

Good point! Ill see how playable it is. It looks quite quite good though. =) maybe when its finished i am going to decideit i try to bend it back.

[MaliGn]

A very very long time ago I did some sand textured terrain by combining UHU glue from a child's glue pen (clear, runny pva type glue) and sand to create a sticky sandy substance and applied this gloopy mess to the bases of the scenery I was building, when it dried it was absolutely solid. I would be inclined to do something g similar again, but would probably just use a mix of water, pva and sand all mixed together in a tub.