# What glue for securing dirt to plywood for authentic scenery?



## Brother engineer (Feb 2, 2021)

What works best for securing dirt or coffee grounds to plywood for authentic scenery. Clear guess not the best results?


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## CTValleyRR (Jul 26, 2014)

What does "clear guess not the best results" mean? You can use anything sticky... even latex paint. Paint your terrain brown, and sprinkle the dirt / coffee grounds in it while it is still wet. I personally use artists matte medium (diluted 1:4 with distilled water) as an adhesive. I "paint" an area with a thin layer of the full strength stuff, sprinkle on some ground cover, and let it dry. This gives the terrain some tooth to hold more ground cover. Then I go back an apply the ground cover in the desired thickness, then mist it with diluted isopropyl alcohol (70% store strength, diluted 50% with distilled water), followed by a heavy mist of dilute matte medium until it is saturated. While you can use any spray bottle for this, I prefer those used by hair stylists -- it has a small pressure cylinder that you pressurize by pumping, but it then gives a very heavy and even spray independent of the pumping motion, so it's less likely to blow your ground cover around.

You can also use any brand of white glue, Mod Podge, or wood glue in exactly the same way. Spray adhesives also work, as does cheap, unscented hairspray. There are so many ways to do this -- and certainly not one way that is better than all others. You have to experiment and find one that works best for you.


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## Brother engineer (Feb 2, 2021)

Thank you so much for your excellent ideas. I meant to say white glue didnt work too well. I'll give it a try and see what happens.


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## Mixed Freight (Aug 31, 2019)

Brother engineer said:


> What works best for securing dirt or coffee grounds to plywood for authentic scenery. Clear guess not the best results?


Elmer's Glue-All white glue, or Mod Podge *Matte* Medium (NOT Gloss), would work just fine. Mix approx. 15% glue with 85% tap water, with a few drops of dishwashing detergent, in a quart spray bottle for applying. Carefully mist it on over your dirt. You can simply lay old newspapers down to protect areas or items that you don't want sprayed. These glues are white when wet, but will dry clear and flat.

Elmer's can be softened quite easily with water after it's dry, which means you can wet it down and scrape it off later on down the road if you want to make changes. Mod Podge is much more water resistant when dry, so it's considerably more permanent, but some folks claim rubbing alcohol will soften it up nicely. I've never tried softening it up afterwards, however.


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## Lee Willis (Jan 1, 2014)

I used yellow wood glue diluted with 2X times as much water and thoroughly mixied, then brushed on first.


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## CTValleyRR (Jul 26, 2014)

Brother engineer said:


> Thank you so much for your excellent ideas. I meant to say white glue didnt work too well. I'll give it a try and see what happens.


No, full strength anything doesn't work to well. Except to establish a base coat, as I indicated. To Mixed Freight's point: mediums (Mod Podge, Liquitex, etc.) are what artists use to adjust the consistency of acrylic pigments. They come in several "flavors": gloss, satin, and matte, typically. Matte simply means "flat" or not glossy. They're meant to be resistant to wear, fading, and discoloration, as well as somewhat flexible. They are more expensive than glue, but they last longer. And the dilute alcohol mixture will soften them and allow them to be scraped off.

Incidentally, the gloss stuff is a great way to make water features, and the related product, gloss gel, is great for making waves, ripples, rapids, etc.


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## cv_acr (Oct 28, 2011)

Brother engineer said:


> Thank you so much for your excellent ideas. I meant to say white glue didnt work too well. I'll give it a try and see what happens.


Mix it 50/50 with water and "paint" it on. Undiluted won't work, too thick.


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## Severn (May 13, 2016)

And you could spray over it if it didn't stick as much as like with the spray bottle/glue mixture technique.


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## mesenteria (Oct 29, 2015)

Lee Willis said:


> I used yellow wood glue diluted with 2X times as much water and thoroughly mixied, then brushed on first.


I also use aliphatic resin (yellow carpenter's glue) for 90% of all my roadbed and scenery, including ballast and dirt. I'll spray it diluted, or use it full strength, depending on the application. It doesn't show up anywhere as shiny stuff in the scenery, or in the ballast.


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## Severn (May 13, 2016)

So far I have not personally found the elmers to dry shiny when sprayed from a diluted mixture. i guess on top of a either wood or a foam panel -- i've put down the layer of paint, a light brown acrylic usually. and then when wet i put down the ground cover. after this dries i hit all again with more ground cover and the spray until its covered like i want it to be. works for me. i did try a model specific brand of spray glue and while it worked it didn't seem to be any dramatic improvement. the biggest issue with the spray bottles is they clog up. I finally caved and bought a wood land scenics way-over-priced spray bottle one time out of frustration with the my home brew spray bottle approaches -- and low and behold its improvement over them. It still pays to clean it pretty good to flush the tubing if you hit bottom with it... otherwise i think the longer it sits, it will inevitably clog and while these clogs can be flushed out eventually with hot water ... it's a huge pain to do it per use.


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## DonR (Oct 18, 2012)

You might consider covering your plywood with a foam before beginning your
scenery operations. It provides a smooth surface that can accept most any
adhesive. You can easily penetrate it to set fence posts etc.

I used the 1/4" paper covered foam from Walmart, Michael's or
Hobby Lobby. It comes in various colors but black and white are easiest
to adapt to scenery. I used the black for base of my yards...the white for
lawns, fields and the like,

If you plan rivers, lakes, or ditches, the thicker foam available at
home centers and lumber yards make it easy to do your
excavations.

Don


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## CTValleyRR (Jul 26, 2014)

cv_acr said:


> Mix it 50/50 with water and "paint" it on. Undiluted won't work, too thick.


White glue, maybe. Matte medium is not -- it's MEANT to be brushed.


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## johnccaravello (Oct 14, 2021)

Brother engineer said:


> What works best for securing dirt or coffee grounds to plywood for authentic scenery. Clear guess not the best results?


Try a 50/50 mixture of plain white Elmer's glue and water. It thins it out and provides a good surface for spreading scenic powders and lichens. I've had good success with it and it's cheap. I hope this helps.


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## Severn (May 13, 2016)

6 months went by and somewhere in there I discovered this great vid describing some homebrew scenic glue options. Although the white glue mixtures worked for me overall I found certain things not exactly to my liking. Two main things. My spray bottles always ultimately got clogged up. And for some kinds of ground cover mainly dirt like material but even ballast somewhat the mixtures didn't necessarily sink in as well as I wanted sometimes. So I ran into this vid and tried tbe matte medium approach... I tried his mix which is restated in the comments and I think it works better than the white glue mixes.

So I just pass it on here and you can decide for yourself.


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## CTValleyRR (Jul 26, 2014)

Severn said:


> 6 months went by and somewhere in there I discovered this great vid describing some homebrew scenic glue options. Although the white glue mixtures worked for me overall I found certain things not exactly to my liking. Two main things. My spray bottles always ultimately got clogged up. And for some kinds of ground cover mainly dirt like material but even ballast somewhat the mixtures didn't necessarily sink in as well as I wanted sometimes. So I ran into this vid and tried tbe matte medium approach... I tried his mix which is restated in the comments and I think it works better than the white glue mixes.
> 
> So I just pass it on here and you can decide for yourself.


Well, if you've read my previous comments in this thread, you already know I'm a big fan of the matte medium route.


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## Severn (May 13, 2016)

Cool. I just made a batch. I don't know if you can make out what precipitates out of it at the bottom of this jar. But the remaining milky liquid which is watery will flow nicely through a pump sprayer. Or you can drizzle it in various ways also as mentioned.


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## mesenteria (Oct 29, 2015)

I just use wood glue, the yellow aliphatic resin, but diluted a bit. I use it for ballast, for making trees, for gluing 'foliage clusters' and ground foam 'bushes' in place, and of course I spray all my fine ground foam 'grasses' with it as well. Once it dries, you can't tell the difference that it was wood glue, or that it was yellowish, etc.


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## Severn (May 13, 2016)

Some people seem to have luck with this but in my case the diluted glues clogged my sprayers or came out too thick, or as I said didn't sink as much as I thought it should on some surfaces... So I didn't have a solution until I ran into the matte medium mixture above. And it definitely solved these problems for me. Which doesn't mean glue mixtures are gone I just use those where I want a bit more stickiness. Etc...


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## mesenteria (Oct 29, 2015)

Severn said:


> Some people seem to have luck with this but in my case the diluted glues clogged my sprayers or came out too thick, or as I said didn't sink as much as I thought it should on some surfaces... So I didn't have a solution until I ran into the matte medium mixture above. And it definitely solved these problems for me. Which doesn't mean glue mixtures are gone I just use those where I want a bit more stickiness. Etc...


They clog my sprayers as well. I have two solutions: remove the spray head and insert it into a water-filled bottle of the same size/type and press the trigger outside over the lawn about 8 times to clear the tube and nozzle. Or, remove the spray head and immerse it in warm soapy water for 20 minutes. Re-attach the tube, submerge the tube end in the warm soapy solution, spray until the nozzle clears itself. Works quite reliably for me. 20 minutes later than I wanted, though.


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## Severn (May 13, 2016)

I did those things too and got tired of it. The matte medium solution doesn't seem to have these problems


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## CTValleyRR (Jul 26, 2014)

Severn said:


> Cool. I just made a batch. I don't know if you can make out what precipitates out of it at the bottom of this jar. But the remaining milky liquid which is watery will flow nicely through a pump sprayer. Or you can drizzle it in various ways also as mentioned.


The milky sludge is talc, which is used as a dulling agent. Decant the liquid and discard the talc sludge.


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## Severn (May 13, 2016)

Talc huh, who knew...


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## JeffHurl (Apr 22, 2021)

I learn something new just about every day here!


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## CTValleyRR (Jul 26, 2014)

I learned about that the hard way. I was getting white spots on my ballast, and asked a fellow modeler if he knew why. He asked if I was discarding the talc that precipitated when I made the solution. I probably gave him a very confused look at that point...


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## scenicsRme (Aug 19, 2020)

I learned recently that Elmer's white WOOD glue sold at hardware stores etc IS aliphatic resin glue, BUT Elmers white SCHOOL glue that is similar in appearance to their wood glue, is a STARCH Base product similar to wallpaper paste, and is only good for paper. This so if a little rug rat drinks the bottle of school glue it won't hurt em.


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