In-ko-pah RR: Dos Manos depot

[Hydrostat]

Ray,

I saw your last post after Russ' answer and so the first picture I faced was the 'concrete casting' and I thought 'oh man, how did he carve that out this clean?'  . Very clever and convincing solution. For sure we're watching an(other) artwork come to life. The drain tubes will give reason for some nice stains, I think ...

Happy new year!

Volker

[Allan G]

It keeps getting better and better......Allan

[Peter_T1958]

Hi Ray

I like a lot your work with that Sintra board. But those sandstone blocks on the lower portion of the building are a real eye-catcher. Thank you for the very inspirational link to your homepage!
Without a coat of putty on the face of each block your technique could eventually be used for rough-hewn limestone blocks, as they are common in my area.

I will save this on my harddisk for future projects!

Peter

[Ray Dunakin]

Thanks for the comments, everyone!

I got a little work done making doors and windows. On the freight doors, I started by scribing planks and wood grain onto pieces of 4mm Sintra:




The trim was built up using styrene strips. Here's one of the finished freight doors temporarily installed on the building:




Next I made the small windows for the west wall of the baggage/freight room:






The windows for the main part of the depot are a bit more involved. My standard method simulates the appearance of a sash window, but uses a single piece of glass. I start by putting together the frame that fits into the opening, then add the "bottom" layer made from wider strips. The sash details are then added:










And here is one of the finished windows, temporarily installed:

[Ray Dunakin]

Got a little more done...

The doors were built up from styrene strips, in much the same way as the windows:






Here's one of the doors temporarily installed on the building. I haven't added the doorknob yet:




I added the structural components for the bay window:




The window frames were built separately. Here they are temporarily installed:




The silicone molding compound I ordered arrived yesterday, so it looks like I'll start work on the Spanish tiles next.

[Scratchman]

Ray, your work is always so neat and clean.

Gordon Birrell

https://www.flickr.com/photos/gordonbirrell/

[finescalerr]

Quite satisfactory. -- Russ

[Bill Gill]

Ray, This is all excellent. A pleasure to watch progress.

[Ray Dunakin]

The next stage of the project was a bit of an adventure...

I made some Spanish tiles using 7/16" (.438") diameter styrene tubes. I marked lines on the tube lengthwise, dividing it evenly into thirds. Then I scored these lines with a sharp hobby knife. I used the extruded aluminum rail on our patio door as a guide to draw and score the lines. Then I cut the tube into 3/4" segments:




After sanding the ends of the segments, I snapped them apart along the scored lines. This gave me three tiles per segment, each about 3/8" wide:




Next I sanded the edges to a slight taper, making them narrower at one end:




Now, I could have just gone ahead and made all of them like this. However, I wanted to try making a mold and casting them in resin. Although the shape is simple enough for a one-piece mold, the tiles are so thin that it's not possible to pour the resin in and get all the air out. So I would try using a two-piece mold.

I built a small box which is held together with screws. Most of the box was made from 6mm Sintra. Only the top piece is styrene:




The tiles were glued to the inner side of the styrene top, using a solvent:




To make the first half of the mold, I had to fill half the box with sulfur-free, plasticine clay. I held a piece of Sintra against the tiles to support them while I pressed the clay around them. I had set the clay in front of our small, electric space heater for a few minutes so it would be soft and supple:




Then I used the blade of a small screwdriver to press tiny bits of clay into the gaps and smooth it around the tiles:




The styrene top was secured on the box, with one side open. Then I finished filling the box halfway with the clay, again using the screwdriver blade to smooth it:






I used the end of a paintbrush handle to press small dimples into the clay. These will form "keys" in the silicone to aid in aligning the two halves of the mold:




I taped the corners of the box to prevent any possible leaks, then filled the box with silicone molding compound. (The brand I use is Oomoo 30.)




After the silicone had set, I removed the bottom and one side of the box so I could access the clay. The clay easily pulls away from the mold, especially if it's not warm:




I cleaned out all bits of remaining clay, then replaced the bottom piece of the box. Next I brushed petroleum jelly onto the silicone, thinning it a little with paint thinner. It's very important to cover the silicone completely to prevent the two halves becoming one. Then I poured in the second layer of silicone and let it set:




After the silicone had set, I disassembled the box and pulled apart the two halves of the mold. These were coated with a mold release spray that I bought at Michael's (craft store). The spray was allowed to dry:




The resin was dribbled into one half of the open mold. The mold was then closed and quickly set upright. I used two bricks to keep the halves of the mold pressed together. Extra resin was poured over the top to replace any that leaked out. This method worked, but it's very messy and wasteful, getting resin all over everything. It also required a few tries to get the best results. After an evening of making castings, I had about 80 useable tiles.


The cast tiles had a lot of flash that had to be sanded off, as seen on the left and middle tiles in this photo:




Here are several tiles after sanding:




Sadly, I came to the conclusion that although the tiles could successfully be cast, the process was too slow and labor intensive. I can make them individually from styrene tubes just as quickly, if not quicker, and with a lot less mess and waste. Which is a real shame, because that two-part mold sure turned out nice. But at least it provides a good "step-by-step" on the mold-making process.

[Gordon Ferguson]

Always look forward to your updates Ray as there is so much to learn and enjoy from them.

Very occasionally I feel I can contribute to your builds .......... And in this case for your tiles can I suggest you consider the method Pete Hamann used for his 1/35 Spanish house.

Pete, first of all made the 2d shape of the tile out of brass strip ( like a cookie cutter). Then rolled out a sheet of modelling clay , cut out the tile shapes with the "cutter"  and then before clay had hardened draped them over some tubing to get the curvature on the tile.

Now think Pete used one of those air hardening clays , with your outside use that type of material might not be up to the job but either the clay you can bake in the oven or one of the epoxy type (Milliput) would be up to the job

Pete is on FB and sure his technique is shown there in one of his folders

[finescalerr]

Alternatively, maybe one of us could draw tiles for you in 3-D CAD and you could print them. And I'll bet somebody else also comes up with an idea. -- Russ

[Bill Gill]

Ray, As I was reading along on your very through S-B-S description of casting those tiles, a little voice kept saying 'that looks like more work than all the effort to make them individually. BUT... the process was very informative and useful in the future.  And, it's the extra work you're willing to do to fabricate details to look like they're supposed to that makes your models such a pleasure to see!

[lab-dad]

What about doing a "row" of shingles? overs and unders for lack of a better term?
-Marty

[Ray Dunakin]

Thanks for the suggestions, they are all appreciated. At some later date, I would like to experiment with molding and casting several rows at a time. But for now I'm just going to make the tiles individually from styrene tubes, combined with those I've already cast. This project has already taken much longer than I'd planned, and I need to get it done.

I think the problem with 3D printing is that I need many hundreds of tiles, enough to cover over 150 square inches (plus ridges). Since the tiles overlap end to end and side to side, that's a LOT of tiles. Probably would be very expensive to print.

The clay-and-cookie-cutter method is something I'd considered, but I think it would probably take more time and effort than what I'm doing now.

[Sami]

Ray, I always like your job. The windows and the doors are beautifuls !