Structolite Coverage

xrayvizhen,

     Of course the answer to that question depends on how big of an area you are trying to cover. I am not sure anyone can give you sq ft coverage since the original use for structolite is not meant for how we use it. Structolite is slow to harden, so you do have time to work with it. My advice is to start out with less than you think. You can always easily mix up more. My technique was different since I used plaster cloth and then spread structolite over it.

      One thing you would like to do is use all that you mix up on your layout and not have to discard any. Not only to conserve your structolite, but also the problem of discarding the extra. Wherever you put it, it will harden. I would even advise using a bucket of water to wash your hands and not get any down a drain. It does work great on the layout though!

Rick

Rick is correct. I sometimes wipe the extra off and others I slather the extra on it with my hands. I use a heavy duty towel and i get it wet/damp before I put it in the mixture. I like the long set up time so you can do a lot and get a better idea of how it looks. One bag does go a long way.

I would be interested in knowing how much 80 lbs covers. 65 sq ft requires about 4 lbs of fusionfiber.

If you have trouble with the structolite/towel method, one alternative to consider is the use of plaster cloth rolls.  They are fairly inexpensive and come in small, individual packages, in a case of 8 to 64 units, so you can avoid dealing wtih a large 80lb bag of construction material which can get messy.  Just lay the plaster cloth strips over your cardboard/wire underlayer and spray water with an atomizer and let dry!  It is very forgiving and pretty clean to use.

http://www.jerrysartarama.com/...ster-cloth-rolls.htm

That's a pretty good price for plaster cloth. I used some Woodland Scenics product which worked well but is expensive...about $1.00/sq.ft. Actually it's double that because you need two layers. The source you have there seems to be about half the price per sq. ft. of the Woodland Scenics stuff.  Well, the 80lb bag is in the basement and it's not going anywhere else so I'm going to use it. Structolite is only about $11/bag. Add-in the cost of the paper rags and it seems to be the most efficient way to go cost-wise. 

The best part of structolite is the working time.  Almost 4 times that of hydrocal.  Also you can 'work it' unlike plaster.  While it is still damp you can scribe it, add coloring, add ground cover, etc,.  I also use it to fill in around rock cstings as it has a great texture to it.  I mix it in small batchs in a flexable tupperware bowl.  When dry just flex the bowl a little and out comes the leftovers.  BTW the leftovers get used in the rock slides and right of way dunnage.  Have fun!  Russ

an old theater trick is to coat your fabric with a mix of white glue and paint thinned slightly with water.. that will give you a stiff. workable base for you finish coats, Hydrocal is a great top coat but the material you are using has the added benefit of texture..

Are you planning to model Mt Rushmore - 80 lbs wow.  80 lbs is going to go far.  I use the 20 min hot mud so I can cover more area quicker and come back a work on it after it hardens the same day.  I use it and 5 minute hot mud in my rock molds.  I mixed it a little thinner than peanut butter and wore rubber gloves.  I coated the towels by wiping the plaster on the towels and then laying them over the cardboard frame.  then after I got the whole area covered, I took any left over mud and rubbed that all over the area I covered with the towels.  I can judge pretty well how much to mix up in a batch. The loose left over mud is good to smooth out any transitions between the towels and plywood.

I have used the plaster cloth method and then put structolite(gypsolite) over it.  The nice thing about this product is that you can mix it to any consistency you wish.

I have not used it using the dip in towel method and not sure about the results due to the aggregate (perlite) in the plaster which makes it rough or sandy like.

I did see on the USG web page that structolite should give you coverage of 140 sq yard per ton which equates to about 2 sq feet per pound however this is based on a base coat over lathe.  It will probably go further than that for the towel method but less if you go and slather on a coat over the base towels afterward.

Hope this helps!

Thank you! Now that's some concrete (no pun intended) information. I should have thought to look at USG's website but the fact that you say you can mix it to any consistency is very helpful since I will probably use it in several different ways. I have to go over some plaster cloth so for that I'll probably just trowel or brush a thin layer on. I have some areas on top of a foam cliff where I have to fill in some gaps as well as cover up the foam so for that I'll use some towels dipped in a looser mix. And then I have some vast areas that will go over cardboard lattice which again will be with towels but maybe in a denser mix so the stuff doesn't drip all over the place.

Information strictly on the various ways Structolite (or Gypsolite) are used would be much appreciated.

I bought a 50lb bag of gypsolite and some 5 gallon buckets with lids.  As soon as I bought the gypsolite I put it in the buckets and sealed them up tight.  I have had it for two years and it is still good to use!  Just keep the moisture out and it should last a long time.

And as I said before this is very "gritty" so if you want smooth you will probably still need some hydrocal.  Also you can not use it for casting rocks or anything else in a mold.  You will also need hydrocal for that as well!

I actually used almost two 50 pound bags on my layout since almost everything that was covered by plaster cloth was also covered by Structolite. I just liked the texture that it left even on surfaces that were only painted and not covered with scenic material. Of course, I did also have mountainous terrain!

11'x14' island layout with scenery rising to 7 ft = 225 lbs of Structolite.

Coverage depends on thickness applied. I used at least 1/4" overall for strength since this store layout would take much abuse from enthusiastic visitors and mountain climbing felines.

Jim

OK, now I'm getting confused. After doing more research and looking at a lot of You-Tube videos I'm starting to think that maybe Structolite is not the right product to use for basic hard-shell...the paper towel over cardboard lattice method.

From what I've read, most people use it on top of plaster cloth or something else that's already been applied or to fasten rock castings to the hard-shell that's already been applied. I like the plaster cloth method but it's easily the most expensive way to go, even when buying from the place catcarlines mentioned. I've used Hydrocal too in the past, but it gets hard way too fast to suit my pace. So before I rip open that big bag (and I looked again...it's 50lb not 80...it only felt like 80 when I lifted it out of my trunk) can Structolite be used as the base hard-shell?

No, I made the cardboard lattice and lay the dipped towels over the lattice.

As in most things we do with scenery on our layouts, there is more than one way to accomplish what we want. Sometimes the best way may be way too expensive for the everyday modeler. I think you should experiment with the method that you originally wanted to try. Do it on a small area of the layout and see how you like the results. I think it will work. Plaster cloth can get expensive and I have tried to cut corners as much as I can. I found a source that has plaster cloth also for good prices at times. American Science  and Surplus. They have all kinds of things and at times good prices on plaster cloth. I would mix up a small amount of Structolite dip your towels in it and see how that works. Be prepared, it will be messy, so protect your track if you have any secured down in place. But that goes for plaster cloth too…it is just a little easier to wipe off any areas that may have gotten splattered onto the track.

   I like the plaster cloth method first and then the Structolite over it which gives a great hardshell that you can add scenery to. I drilled through it to add trees when the time came. 

Sure you can. It's just a little messier dipping paper towels rather than using the plaster gauze material for the basic landform shape over cardboard strips.

I use plaster gauze for small projects, but dip towels in Structolite for big projects where the plaster gauze would be too expensive.

I still use an additional layer of Structolite over the hardened towels for additional strength.

Jim

Drywall Plaster should not have any grit or rough finish to it.  20 minute and 5 minute hot mud would be absolutely worthless if it has grit in it.  I don't have access to Structolite so I have know idea what is in it or why it would have grit in it. 

I use mainly Westpac Fast Set 20.  I use it on my interior walls on my house, work, etc.  It was a pretty easy transition to use it for rock molds and terrain on my layout.  I have made hundreds of rock castings with it and had zero problems.  I do spray the molds with a water with a few drops of soap solution before casting.

The reason why hot mud is the best way to go is that it is designed for Drywallers/plasters to finish a job quickly, it has to lay down smooth, harden quickly, not shrink or crack.  20 min hot mud is the best solution for castings as you can pop the castings out quickly and make a bunch in one day.  It is also great for shell work as it hardens quickly.  20 mins is an eternity.  They sell it in small boxes (if you want to test it), you can get fast set 90 if you are not sure, but for castings after you get the hang of 20 min, you'll move to the 5 minute hot mud.

I think on the east coast the similar product is Sheetrock Easy Sand 20 Setting-Type Joint Compound.

Rick, Jim

I'm glad I'm not the only one that went crazy building mountains.

Larry

Considering that I have come to the realization that I have little or no artistic talent I will use the Structolite with the paper towels over a cardboard lattice and see what happens. Would I still use the 2:1 mix to water ratio or would I need to thin it out for the towel dipping method? 

I consider myself on the very, very low end of artistic talent, but with a great big desire to have scenery that mimics real scenes as best as possible. It is mostly trial and error and even the errors can be made worthy to the eye. As for the mix, I am betting that you might want to make it more fluid than what I did for the hardshell. And, as to the formula? That is what is great about Structolite….too thick? Add more water. Too thin? Add more Structolite. You have time to work with it. And, don't be afraid. It is somewhat forgiving. The tougher part comes when painting and making it real as possible. That is really where I fall short.

Rick

I can see where the grit can be useful for terrain modeling.  I would get a box of accelerator.  Even if you temper it for a 90 min set up that is plenty of time to work with what you can mix in a 5 gallon bucket. 

I had an area between some tracks, not large, but I added some cardboard frame work,  used the 20 min hot mud, stuck my precast rocks on with the mud and was painting, adding gravel, sand, ground foam and shrubs in a hour.

"Anybody remember the linoleum paste articles"  Before grocery stores went to plastic bags - anybody remember paper bags - great scenery material for plaster 'dippin'!  Russ

paste I remember using wall paer paste smelled like old tea bags was gross to work with and did nothing. thos eold brown paper bags were mostly Hemp which was banned when the "war against drugs" was started. those things were tough I guess the plaswtics industry had some pull hence we now are stuck with crappy tear as soon as yo9u leave the store plastic bags..

the new paper bags are dyed wood pulp and no where hear as strng.

 the old paper bags you could mulch done with water. shpe and have a really tough product.

You have a right to be confused... After reading the entire thread and being in the middle of doing my landscaping, I will take the liberty to summarize. 

There are two main schools of thought, and frankly, both will deliver nice landscaping. Technique 1 is to use plaster cloth and then cover with Gypsolite/Structolite (same product/different manufacturers) to add bulk and texture. Drawbacks are the expense of plaster cloth. Since you can't successfully use a fast setting plaster as a pseudo-plaster cloth due to working time, you're sort of stuck using commercial plaster cloth. It is easier and it's much less messy.

The second technique is to use the long-setting plaster with paper towels to make your own hard shell, and then treat that. I say, "treat that" because in my experience, a single layer of paper towel/Gypsolite is not strong enough. I had some areas where the plaster impregnation was less than optimum and it started cracking and in one case I put my hand through it. Therefore, you need to add something else. In my case it's Sculptamold. 

I personally felt that the rough texture of Gypsolite was too rough. I wanted a smoother, more controllable surface. But Sculptamold defeats the cost savings of using Gypsolite in the first place since it's over $6.00 a bag and I've gone through 7 bags already and barely have one end of the layout in terrain. There's a whole other end that's going to get a mountain and more terrain that will probably consume another 7 bags. That's over $80 worth, versus the <$20/50 lbs for the plaster. Oh well...

But after reading this, I'm probably going to try and use some of the more textured materials for top coats and see what happens.

After doing a bit of research and looking at costs I have come up with the following information:

Structolite  $0.23 per lb

Gypsolite   $0.12 per lb

Ultracal 30  $0.58 per lb

Hydrocal     $0.66 per lb

Sculptmold  $1.90 per lb

Rich Batista used the towel and Hydrocal method for his base coat over cardboard web and HD contractor paper.  After setting up he applied another coat of just Hydrocal over the original shell for additional strength.  This left a very smooth finish on his landscape but then he applied rock castings over the smooth finish.  He filled in gaps and other areas without rock castings with broken up dried plaster mixed with fresh plaster.  His results are outstanding.  He also used the Hydrocal for his rock castings so only one product to buy.

Dave Frary uses the plaster cloth method with an additional covering of gypsolite.  He also uses the gypsolite to attach his rock castings and fill in the gaps in the rock castings.  His results are also outstanding.

For Rock Castings I would go with Hydrocal or Ultracal 30 which are both available from USG direct.  The Ultracal 30 is probably the best product for rock castings but I am not sure about it's use for hardshell since it doesnt have an impact rating!  Hydrocal can definitely be used for both.

Still not sure if structolite or gypsolite with paper towels will work to well due to the aggragate (perlite) in the material.

For me when I get back to scenery I am going to use hydrocal and paper towels for initial shell structolite for second coat and rock casting attachment and Ultracal 30 for my rock castings.  Oh and I am going to use plaster cloth for the small jobs when I dont want to make too big of a mess!

Hydrocal sets at about the same rate as plaster of paris, extremely strong

Ultracl sets much slower is a gelatinous material that is highly plastic, it runs and sags like crazy. because of the slow set time and excellent flow out t drys with a high level of cross linking.  it is very inert once cured and drys like china... right down to the way it breaks.

mix the two together, a perfect material for hard shell I usually run 2/3 hydrocal to 1/3 ultracal.. 50 50 for making rock molds.

when mixing the above plasters, start with water, sift the plaster into the water until it appears liek a dried lake bed.. let it soak for about 5 minutes, then mix thoroughly, use your hands to make sure there are no lumps..

when using molds, try buttering the molds with plaster and then placing mold and all on the surface you are coating while still wet.. it will conform to the surface and each cast will appear different because of the distortion

a rock mold is what you pour the plaster in a rick casting is what you get out. I know picky picky

Each time I read this thread I learn something new!

Since I’m the guy who started this particular thread I thought I’d offer my first impressions of using Structolite as a hard-shell base and elicit some comments or tips regarding what I did and didn’t do right and what I should do going forward. 

I mixed up several small batches of Structolite today one by one, 32 oz of material into 16 oz. of  water, mixing slowly and using my rubber gloved hands to mix which incidentally was much better than using a paint mixing stick. I dipped Scotts “Rags”, a heavy paper towel cut into roughly 6” x 12” pieces, into the mix and started applying to a cardboard lattice I had prepared and discovered a couple of things. #1 is that 32 oz. of Structolite and 16 oz. of water covers maybe 2 1/2 square feet and that’s it. #2, and maybe I soaked the paper towels too much, but the cardboard lattice, made with 1” corrugated cardboard strips separated by about 4”, started to sag under the weight of the material. On the attached picture you can see a lattice that started out convex became concave after a few minutes and this was a vertical surface. On a flat area (not pictured) the problem was even worse. I think in the future, I’ll need to supplement the lattice with balled up newspaper or something else. You can also see from the picture that the checkerboard pattern of cardboard strips is showing through so I’ll need to cover that up with something else as well. Maybe an entire second layer of paper towel impregnated Structolite?

This is all setting up as I type this so I don’t know what the final result will look and feel like once it gets hard but in summary, this is certainly a less expensive way to go as compared to plaster cloth or Hydrocal but obviously I I’ll need to overlay what I did here with something additional and fill in the gaps and holes.

Suggestions on what to do going forward would be welcome.  

Besides more support, that's precisely why I overlaid Sculptamold onto the hard shell to give it the contour that I wanted. I also used screen wire on areas. I only used cardboard strips where they were short enough to be nice and stiff. Even the screen wire needs some under-structure to hold it shape with the wet, heavy plaster on top. You can always embed rock molds into the Sculptamold and make that cliff face look great.

You can make a tighter cardboard web. I hot glue some of the strips to each other and I have covered the web with weed block material so that excess does not fall onto a track area that runs under that area.

Everyone can do this in so many ways, so I will chime in again. I believe that no matter how close your web of cardboard strips are, you will still see some sag. I did using plaster cloth first. But, coat of Structolite that I put on second smoothed any noticeable areas and eased the contours. The Structolite gave it great strength even though the shell was relatively thin. By the time one paints and then adds ground cover and other scenery, it all begins to blend in. I also hot glued on the rock molds I made after the plaster cloth dried and before I put on the Structolite layer. One could also effectively use the Sculptamold at this time too. 

Oh, and the forms that you see the mountains built upon, they are wood frames with plastic needlepoint forms over them. I wanted to build interiors to the mountains so that they had a bit of realism too….I knew I was going to have a camera mounted on the engine to see it go through the tunnels. So, I finished the inside with crumbled paper painted black.

I use fast setting plaster all the time successfully. It comes in 5 min, 20 min and 90 min, some brands make 45 min and/or 60 min. When I make rock molds I prefer 5 min, but because I have a bag of 20 min on hand all the time, it usually becomes the standard.

You can mix a nice size batch of the 20 min and get a lot done fast and the benefit is you can go back and work on those section again in the same day. I think there is much unfounded fear with these products. I have finished enough drywall and drywall repairs that I will no long work with anything else and my home requires the work needs to look nice. Troweling on drywall mud for the interior walls of my home is 1000 times more technical than using it to make a shell with paper shop towels.

There is no right way or better way, just a bunch of different ways to get to the same goal. I am not retired, my time is limited so I just adapted what I know from finishing drywall into making terrain with hot mud and it has worked for me and works very successfully.

My approach is similar to Rick's.  The one thing I would add is that  when doing vertical cuts or rolling hills, I get better results by using heavy construction or butcher paper rather than a cardboard grid.  Then there is no problem with undesired sagging.  On rugged mountains, some sagging is desirable.