I recently had some questions about several DIY products which might be suitable for miniature stone work. While there are products made just for artists, such as a variety of air dry clays, these are expensive, by comparison, and often unavailable.
Here is what I’ve learned…
Dry wall/joint compound or “mud”:
Paste-like material, used by building/construction contractors to fill in the seams between sheets of drywall...also called “sheet rock”. These sheets replaced plaster and lathe many years ago. This product is usually mixed at the site from a powder but is available pre-mixed in smaller quantities.
It takes at least 24 hours to fully dry. Can be sanded smooth or left sculpted for a textured look. Usually dries grayish white but can also be obtained with a pink tint for second coats after the first sanding. That helps the drywall guy find where he needs to do a second sanding after a re-coat.
This stuff has a lot of water in it and the substrate (especially paper-coated foam core board) can easily warp. It will also add weight to the project. You will need to paint this product unless you are going for a really rustic or aged look but it takes paint and washes and stains well.
Heavy duty or heavyweight vinyl spackling compound/paste:
Another paste-like material used by builders or DIY-ers for major repairs to drywall or sheetrock. By major repair, I mean a large hole or crack in the wall. This product dries slowly also and requires several applications to fill the hole. It has a consistency similar to the drywall mud (almost like peanut butter without the stickiness…). It also dries to a grayish white; it can be sanded and painted. I have never seen this product in powder form but it is available in a variety of pre-mixed quantities and stays soft if kept air-tight.
Both the joint compound and vinyl spackle can be sculpted into brick and stone after they have set up awhile, using the usual tools. Both can be textured, sanded, painted and stained. Both can be pre-tinted with small amounts of acrylic paint. Both products will add weight to your project…which is the biggest downside. Both products can crack if they dry too fast or are applied too thickly…or if the project crashes to the floor…
Light duty or lightweight spackling compound/paste:
This product is used to make small repairs to drywall. A “small” repair would be filling in nail holes from pictures or a dent.
This product has the consistency of buttercream frosting. It is very light and airy.
It can be pressed into place with your fingers or smoothed with a variety of tools. It does not require sanding. I use a palette knife or old credit card to texture it.
It is pure white and dries pure white but can be colored with powdered tempera paint. Adding liquid paint can thin it too much. However, since the product can be revitalized with a small amount of water if it becomes too stiff, adding paint shouldn’t be a problem if one is careful. It dries very quickly and can be painted within a few hours. I have only seen it available pre-mixed in the US. Storing in an air-tight container keeps it soft and spreadable.
I don’t think this product would sculpt into bricks very well but it makes a great “plaster” or “stucco” wall and grout for mini tiles or bricks. One of the pluses is that it doesn’t add much weight at all to a project. And that’s a big plus. It also doesn’t seem to crack…at least not in my experience.
CAUTION: NEVER wash any this stuff down your sink…ever! Unless you are a plumber or a close friend of one.
After wiping your tools with paper towel, wash them in a large bucket of warm water and discard water outdoors. Wear gloves as it will dry out your hands.
Regarding warping. All these products contain a lot of water and when they dry, the water has to go somewhere. Some of it evaporates outward but some also soaks into the substrate. I always seal both sides of the substrate with something before I apply these products. Most times I used white glue. It doesn’t always prevent warping but it sure makes it less than if it wasn’t sealed. The only thing I’ve not observed to warp is ½ inch polystyrene.
So take a trip to the hardware store and look around. You never know what you’ll find!
Tabitha
8 comments:
Great info Tabitha. I love the ease of using lightweight spackle, I like to mix acrylic paint into mine to tint it. I had no idea you should not wash your tools in the sink :( These products are a lifesaver for us miniaturists who live in rural areas.
Victoria ❤
Great post Tabitha. I am always looking for ways to cut costs for exteriors and have avoided paperclay as it is soooo expensive in the UK - about 8$ for 4oz! Ouch! Which means importing from the US.
I have used ready made Polyfilla which is very easy but have not thought of sanding it for a change of look. I have bought the UK version of 'mud' for my next project after advice from Michelle and yourself, so many thanks.
I love the look of this stuff it looks fun to use. Alas I have failed to see it in the UK. We have other wall fillers so I think that's 'our' version of this stuff.
I don't dump anything down the sink and always clean off any residue left on tools. I couldn't cope with the row or mess that would ensue if I did! lol Everything goes in the bin!
Thanks as always,
Michelle xx
Sealing with "something?" What should I use to seal MDF (medium density fiberboard) before I paint it? I've read that latex/water based primers are too wet and can cause the wood to warp. I don't want a warped garage!
Any ideas?
I love this lightweight spackle stuff. Does a great job to grout tiles!
I'm sorry, Kathi, I shouldn't have been so vague. I often use white/pva glue brushed on to seal MDF. I have also used a spray primer...or gesso...or matte acrylic medium. All you are aiming for is to prevent water from soaking into the MDF so it doesn't have to be a thick coat of whatever you use. And truthfully, I only do this if I am working with a flat, unsupported piece...like a wall before building. If I am painting after construction, I just paint.
I think the easier thing to use is a clear spray acrylic sealer in a matte finish...and you can easily do this after your building is constructed. Deft makes one that should be available at the hardware store as woodworkers use it. Artists also use it so there are several brands available at stores that carry artist's supplies. Plaid and FolkArt both have one.
Hope this helps. Good luck with your garage!
Tabitha
Kathi,
I have used two types of sealant(see my blog), but as I'm based in the UK I won't name them as I don't know what brands you can buy in the US. Susan (Tabs) has suggested white glue to seal the wood (MDF is the worst medium for warping).
To be honest MDF warps whatever you use....more or lesser amount. I would advise that you seal your project after your project is glued together and then apply your wall covering.
If I have a front of a dollshouse, door etc that would need to be fitted, I fit (not attached yet) it in it's slot whilst the walls are drying. This is to ensure that the front etc will still fit if the walls expand whilst drying.
Michelle
Michelle, I am amazed at the number of people who don't think twice about washing this all down the sink! Like the guy who did a remodel on my former house...I jumped all over him. He probably knew but just didn't care...
When I was in school, the sinks in the Art Dept. all had plaster traps but maybe students aren't always told this? And many DIYers just read the clean-up directions which say "warm water and soap". I thought it was worth mentioning as there are no such caveats on the packaging.
Great information - thankyou!
I mix PVA wood glue and water in a 1:1 mix to seal MDF, paperclay and wood. It goes on easier than straight PVA. And I agree with Michelle that it's better to work on walls after they've been glued together, if it's possible.
And thanks for the heads up on not washing stuff down the sink!
Glenda
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