Scenic cement, matte-medium, Mod Podge matte?


Matte-medium + surfactants: Which ones?

I was experimenting with gluing my non-sanded grouts that I use for dirt and some ground foams and tried Woodland Scenics' scenic cement. I was impressed with its performance. The scenic cement didn't discolor my grout, and everything sealed up nicely with no loose grout powder remaining.

I was about to place another order for more Woodland Scenics' scenic cement until someone mentioned that I can just dilute matte-medium 1:3 to make my own scenic cement. Two of the most common products I see used by modelers are: Scenic Express' Matte-Medium concentrate, and Mod Podge Matte. However, comparing Scenic Express' matte-medium concentrate to Mod
Podge Matte [edit: Mod Podge matte is simply diluted PVA], I noticed that there's a significant price difference.

One gallon of Scenic Express concentrate is $58.98, whereas, one gallon of Mod Podge is only $29.26 (Scenic Express also sells a "prepared" matte-medium for $22.98 a gallon, which I assume is simply diluted matte-medium concentrate). If the Mod Podge product is of similar concentration and formulation, it's clearly the better deal.


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I know that many modelers make their own home-brew Elmer's glue-based scenic cement formulations, and are happy with its performance (i.e., Elmer's white glue + surfactant + water). However, apparently there are a few differences between Elmer's-type home-brews and commercially prepared matte-medium formulations.

I did some Googling comparing the two, and many claimed to prefer commercially prepared matte-medium, stating that matte-medium dries to a more rubbery texture with some flexibility, whereas PVA home-brews tends to dry harder and more brittle. Some stated that matte-medium glued scenery was also easier to pull-up (i.e., comes off in large pieces), whereas PVA-home brews would come up with more difficulty (i.e., pulls off in little pieces). Also, others said that PVA-home brews would tend to darken certain materials, whereas commercially prepared, diluted matte-medium did not.


Since the Mod Podge matte-medium is reasonably priced, I'm inclined to buy a bottle of that for making my own scenic cement and for using full-strength matte-medium when needed. My questions are:

• Is diluted Mod Podge in fact, virtually identical to the Woodland Scenics' scenic cement product?
• Is Mod Podge Matte about the same concentration as Scenic Express' Matte-Medium Concentrate?


My primary application for scenic cement is to apply and seal my non-sanded grouts and ground foams. I plan to use full-strength, matte-medium to apply my static-grass.


Thanks for any replies!
 
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Surfactants:

I first bought a 16 oz. bottle of Scenic Express matte-medium concentrate (before I knew any of the above) when I loaded up on Scenic Express supplies during MTS' 30%-off last Labor Day. At least for the time being, I can make more scenic cement to fill up my little 8 oz. Woodland Scenics' scenic cement sprayer bottle. I really like buying the manufacturer's factory-labeled bottles which clearly indicate its actual contents whenever possible.

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I've read elsewhere that a good scenic cement formula is a 1:3 dilution of matte-medium concentrate-to-water. But the directions on the Scenic Express concentrate bottle recommends a 1:4 dilution, so my 16 oz. bottle of concentrated matte-medium will yield eight more bottles of scenic cement.

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I also bought an 8 oz. bottle of Scenic Express SuperWet hydrous wetting solution (since all Scenic Express products were 30% off at the time), that I plan to use for laying my ballast one day. If I see I need more surfactant for ballasting or other needs, I may pop for a bottle of Kodak PhotoFlo, the wetting agent used in photographic darkrooms. I noticed that some modelers don't bother with soap-like surfactants at all, and choose to use 70% isopropyl alcohol instead. So what do you guys think? Soap-like surfactants or 70% alcohol for ballasting?
 
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When I started my layout, there were very few matte medium products on the market I I ended up simply using Elmers white glue. I would dilute it differently depending on what I was using it for but it has worked quite well for me.
 
I just finished a some research on Mod Podge vs Matte Medium. From the MSDS (now SDS) for each product --

Mod Podge is Poly Vinyl Acetate AKA white glue

Matte Medium is Acrylic Polymer Emulsion AKA co-polymer of methacrylic acid in water

SuperWet is a non-ionic soluble silicon surfactant (its actually a re-packaged agricultural surfactant)

Photo Flo if a mixture of 70% water, 25% propylene glycol, and 5% p-tert-octylphenoxy polyethoxyethyl alcohol

That 5% alcohol is a tertiary alcohol. The primary feature of tertiary alcohols is their higher boiling point, which means they evaporate more slowly than primary or secondary alcohols - think ethanol or iso-propanol.

Just to clarify, since there is a lot of confusion, PROPYLENE glycol is completely safe. Its an FDA approved food additive for both human and animal consumption. It is used to keep food soft and chewy. It gets confused with ETHYLENE glycol, which IS toxic and the primary ingredient in antifreeze.

PS: WS Scenic Cement is an acrylic polymer emulsion.
 
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My questions are:
• Is diluted Mod Podge in fact, virtually identical to the Woodland Scenics' scenic cement product?
• Is Mod Podge Matte about the same concentration as Scenic Express' Matte-Medium Concentrate?

My primary application for scenic cement is to apply and seal my non-sanded grouts and ground foams. I plan to use full-strength, matte-medium to apply my static-grass.

Thanks for any replies!
I cannot answer any of your questions directly. All I can say is that when I tried Mod Podge I was not happy with the results. It never seemed to loose its tackiness. I don't remember thinning it, so maybe that would make a difference.
 
Wow! Awesome work, Kevin! Thanks for doing all that! Since I began this thread I did discover that Mod Podge is simply diluted PVA with some kind of additive to attain a matte-finish (talcum powder?). It's good to know that Woodland Scenics' scenic cement is in fact diluted acrylic matte-medium. As I said, this product worked really well for adhering and sealing my non-sanded grouts and ground-foams.

But I won't be buying Woodland Scenics' scenic cement anymore; instead, I'll be buying Scenic Express' matte-medium concentrate (which I believe is also acrylic-based), and diluting 1:4 as per their directions to make my own scenic cement. A bottle of Scenic Express' matte-medium concentrate, which costs $10.49 for a 16 oz. bottle, will make 80 oz. of scenic cement. That much scenic cement from Woodland Scenics would cost $37.45. Buying a gallon of Scenic Express' matte-medium concentrate ($58.98) would yield five gallons of scenic cement. That much product from Woodland Scenics would cost $300!

My bottle of SuperWet indicates that it contains propylene glycol, so I was thinking, that's some expensive anti-freeze! But, I guess I'm mistaken, and propylene glycol is not the chemical used in anti-freeze. You only use 1 oz. per quart, so the bottle will actually go a long way. Would you recommend SuperWet or Kodak PhotoFlo for ballasting applications, or are they roughly the same products with about the same yield?
 
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I guess I'm into overkill. Bit of history, I've been a avid gardener for over 50 years. Here in New Hampshire, the garden averages around 4000 square feet. Lots of plants, lots of treatments, mostly fungicides, since the cool and damp weather can cause problems. Anyway, through classes at the County Extension Office, I was introduced to agricultural surfactants. So for ballasting, I use BOTH alcohol and a surfactant. Works really well for me. If I had to choose, I'd drop the alcohol from the mix. The surfactant is designed to reduce surface tension. The alcohol reduces surface tension as a side effect. If you want to go with an alcohol, there are much less expensive alternatives than PhotoFlo. Remember it's 70% water and 5% alcohol. The glycol is in the mix to insure even distribution of the solution, water actually having a fairly high surface tension (relative).
 
Well thanks again for doing that bit of research. I suppose the Scenic Express SuperWet is fine. You only use 1 oz. of SuperWet per quart of water, so I mixed up a 1/2-quart into my Scenic Express sprayer bottle which will last quite a while (I still need to buy one of those baby eye-dropper things). I even used distilled water that I had laying around to eliminate any hard-water residue. Scenic Express even recommends adding SuperWet to their matte-medium for better flow. Not wanting any problems, I decided to buy all Scenic Express products for applying my ballast, including Scenic Express' real-rock light-gray and blended ballasts.
 



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