Help - matte medium problem

[nachoman]

I have a goal of having at least one "completed" scene on my layout - that means putting down ballast. I always used white glue in the past, but this time I opted for matte medium as glue. The waterproof quality of the dried medium appealed to me as this is the first time I have hand-spiked rail to wood ties - I want the ties and trackwork to be impervious to moisture changes. Since this is a yard area, I dug up and sifted dirt from my yard to use as ballast.

Here is my problem: I used liquitex brand matte medium from the craft store. It is somewhat on the low-end price wise, and I thought it would work fine for bonding ballast. I mixed it about 1 part medium to 4 parts water and a few drops of dishwashing detergent. I sprayed the area with water and detergent, then applied the ballast glue. This is the same procedure I used when using white glue. When it dried, it left a white "residue" in places on top of the ballast.

Doing a little research, I read that some matte medium has talc in it that may cause this problem when diluted. Some people write that ModPodge brand is cheap and does not do this; perhaps I should try a different brand. Has this happened to anyone else, and does this explanation make sense?

[MasonJar]

Makes sense. I have had little white flecks result from diluting cheap-o white glue, but not matte medium. However, I have not used matte medium in the way you describe.

Andrew

[doctorwayne]

I used Liquitex when I first started ballasting and didn't have that problem, although I used a roughly 1:1 mixture of water and matte medium, about the same as for white glue. I don't put any detergent in the mixture, although I do saturate the area beforehand with water that's had a few drops of detergent added.

The problem could also lie with the dirt used. For the very first area on my layout that had ground cover applied, I used some very fine dust that I'd collected from work - just dirt that had been pulverised by hundreds of trucks, really. While it otherwise looked fine when dried, it also had white deposits on its surface. The results were the same using either white glue or matte medium, so I concluded that the problem was with the dirt. I looks great in the bottom of gondolas, which is now its only use, but I leave it un-glued.

For ballast or ground cover, I prefer white glue over matte medium - coverage is similar for both products, but the white glue is significantly cheaper. The finished appearance is the same, and I don't notice any sound quality differences, as some claim, between the two. The issue of water insolubility on most layouts would be a drawback, as major track changes usually suggest soaking the area with water to soften/loosen the ballast before lifting the track.
Unless your layout is in an excessively damp area, I doubt that humidity will have any effect on your handlaid track. Even if you do subsequent scenery work near the track, as long as you don't disturb anything while the area is wet, your track should survive just fine: after all, you've already soaked it once to do the ballasting, right?

Wayne

[nachoman]

I used Liquitex when I first started ballasting and didn't have that problem, although I used a roughly 1:1 mixture of water and matte medium, about the same as for white glue. I don't put any detergent in the mixture, although I do saturate the area beforehand with water that's had a few drops of detergent added.

The problem could also lie with the dirt used. For the very first area on my layout that had ground cover applied, I used some very fine dust that I'd collected from work - just dirt that had been pulverised by hundreds of trucks, really. While it otherwise looked fine when dried, it also had white deposits on its surface. The results were the same using either white glue or matte medium, so I concluded that the problem was with the dirt. I looks great in the bottom of gondolas, which is now its only use, but I leave it un-glued.

For ballast or ground cover, I prefer white glue over matte medium - coverage is similar for both products, but the white glue is significantly cheaper. The finished appearance is the same, and I don't notice any sound quality differences, as some claim, between the two. The issue of water insolubility on most layouts would be a drawback, as major track changes usually suggest soaking the area with water to soften/loosen the ballast before lifting the track.
Unless your layout is in an excessively damp area, I doubt that humidity will have any effect on your handlaid track. Even if you do subsequent scenery work near the track, as long as you don't disturb anything while the area is wet, your track should survive just fine: after all, you've already soaked it once to do the ballasting, right?

Wayne

Good thoughts there. I considered the dirt itself - this could be a factor since local dirt has a high concentration of carbonates that may evolve to the drying front after being wet with my glue solution. In a way, this is somewhat prototypical because similar happens in real life - leaving white patches behind. I think I am going to test again a few other things before I try a different kind of glue.

[P5se Camelback]

I gotta weigh in with doctorwayne on this one Kevin. I have hand-laid track that I spiked down and ballasted back in 1974 and '75 that has lived in Philadelphia, PA, Los Gatos, CA, Redondo Beach, CA, as well as in a basement in Lansdale, PA (outside Philly) where I installed a dehumidifier which I had running 24/7 in the summer and until I finally ran a line to the sump pump, I emptied a quart or two a week from that thing. Books grew lovely mold and the walls developed an marvelous mildew down there before I put the dehumidifier in. No problems with the white glued ballast.

Those same sections of hand laid track/white glued ballast have been down here in Florida now since about 1991 or '92, at this point enjoying an air-conditioned house. But for about 12 or 13 years, the 6 foot long sections stood on end in an non-climate controlled storage space with no adverse effects to my wood ties, spiked rail, white glued ballast or the Homosote that everything is glued down on top of. The humidity here in the summer hovers in the 75% to 95% range ... actually, it just started pouring now as I type this - the "every afternoon, summer-time, 45 minute, one-and-a-half inch dump" ... and the humidty (outside) is at about 82%. I can barely see the houses on the other side of the canal behind my house, it's coming down that hard! Example ... I waited this one out in the cab of "Horace Dodge" ...



But, fear not ... in an hour or so the sun will be back out, and every thing will be dry - no evidence that it ever rained!

But through it all, the ballast on my track is as hard as a rock, and has been since I sprayed it with "wet water," soaked it with diluted Elmer's (purchased in the gallon container) and left to dry for about three or four days!

************************* edit

Typed faster than I did again, Kevin!

[Russ Bellinis]

Kevin, I doubt that excess humidity is a problem for you where you live!

[nachoman]

Kevin, I doubt that excess humidity is a problem for you where you live!

I was more worried about excess dryness - humidity as low a 2% that dries and cracks wood. I was hoping the matte medium would help seal the wood ties and cork roadbed from becoming too dry and no longer holding my spikes!

[P5se Camelback]

Sorry, Kevin ... I never considered the problems that might be caused by not enough humidity! :oops:

I've never, ever had to deal with that problem. I've only ever lived in places where there has been an abundance of moisture in the air.

[nachoman]

Before trying a different glue, I went back over my technique and tried something different. I mixed my glue to 75% glue, 25% water - the thinning recommendation on the Liquitex bottle. I added no dishwashing detergent to the glue and used an alcohol/water mix to wet the dirt. If anything, the white staining was worse. To make sure it wasn't the dirt, I tried again using dilute white glue as I always did in the past - and it looks great. I think I will stick to just using white glue from now on. After P5se's experience with extreme humidity changes, I am much less worried about the white glue holding up. Thanks for the advice, everyone.

PS, perhaps I will have a photo of my ballasted track in next week's photo thread

[ocalicreek]

Glad you found a solution, Kevin. A bit late to chime in, but I was going to add that I have used white glue and water as a bonding agent extensively on the handlaid track I've done with no problems in shifting track or swelling ties. IN fact, the ties were laid on yardsticks as roadbed with 1/4" ply as subroadbed using yellow carpenter's glue.

I've heard somewhere recently that white glue will carry more sound resonance than matte medium. Supposedly the matte medium is more flexible after drying. I can't say since I've never used it in that way. I have used Mod Podge for scenery work, but most of the time use Sobo or Elmer's white glue. Sobo seems pretty flexible when dry.

Looking forward to the fo-toes.

Galen

[jim currie]

Kevin i seal all the wood on my layout with cheep mistint outside paint to stop the weather from drying out the wood (some of the wood i have got is still green(wet) and the paint helps it from warping)and changing sizes , as far as the ballest(use local sand ) i never had a white film(never used matte medium) but i wash all my ballest before using it.
jim