OK,
I've been using Excalibur, and when my box ran out I decided to try something different. Now, don't get me wrong, I loved Excalibur, but I have bubble issues, and the thickness of the plaster made that even worse. When I thinned the plaster down, I got a concave shape on the back of the bricks after scraping that made it tough to build taller structures.
I dunk my molds in about a gallon of water with a tablespoon of jet dry in it just before casting, and I used to put a drop or two of jet dry in a half gallon of water for the plaster itself (and I used to use a few drops of floor wax as well). The jet dry in the plaster mixing water with Excalibur seemed to produce many small bubbles that had to be dealt with using vibration and an old paint brush to swish it out (Without the jet dry, big bubbles). With the Excalibur, I would dunk molds, mix plaster, slowly pour, vibrate the molds, and sit and watch them...the reason for the watching was it was darn tricky to find the right time to scrape them...the window of going from runny plaster to too hard to scrape was fairly short, and I missed it pretty often. Using this method I got plenty of nice blocks, but the occasional air bubble still haunted me, and uniform block height was always a bit questionable.
So, after reading a bit on the boards I had heard of Merlin's Magic, and from the hype it looked like it was the plaster of my dreams. Cindy at Clint sales sent me a sample of Merlin's, and I made a cast of the same mold (the cobblestone floor tile mold, sure to give you a bubble or two if you aren't paying attention) with Excalibur and with Merlin's magic.
Impressions from the first cast: The Excalibur behaved exactly as I was used to. I had one or two tiles with significant bubbles in them, which is usually the case when I cast that mold. I then weighed out and mixed the Merlin's...and I was *certain* that the mix was off; it was way too thin! But, I figured this was an experiment so I cast it exactly that way. I was sure I was going to get convex, brittle blocks out of it for sure. The plaster settled really rapidly (you know how the pigmentation in it sort of outlines the blocks? Like that) and I sat and watched it to be ready to scrape. I scraped as soon as it hit toothpaste consistency, and left it alone overnight. To my surprise, it didn't "shrink" and create convex tiles, the tiles were the exact same height as the mold itself after the scraping. De molding the blocks was as easy as any other plaster, and there were in fact bubbles...but! The bubbles were very, very small. Small enough a base coat would hide them I think. I was impressed enough I ordered a 50# box.
I've now cast about 30 casts with the Merlin's (man...this box of plaster is going faster than the last one...). And the first thing I noticed as I moved the plaster from its shipping box into my plastic plaster pail (and old kitty litter box, the big ones hold 50# perfectly) was significantly less dust. I usually cast with a dust mask on so I'm not coughing up plaster later. I think I could skip it with this stuff, it really dosen't seem to create as much dust as the Excalibur (but I'll leave the mask on anyway, just in case) I tried every mold I had with it, and pretty much couldn't be happier. I got the gate out of the dungeon builder mold all 10 times I cast it, had very few bubble issues on the corners of the blocks for the Gothic church, but did have a few bubbles on the 2 casts I did of the wood shingle mold, but I've never had much luck with that one unless I go crazy with a brush in it (and I didn't those times, so probably chalk that up to bad technique.) I did notice that it has a much longer window of time that I can scrape it as opposed to the mix of Excalibur I was using, so I don't have to watch it anymore; I go paint a bit on models and scrape it when I get a chance...no missed times so far.
I ditched any additives to the mix (the jet dry and the floor wax) as the jet dry seemed to create lots of really tiny bubbles in suspension in the Merlin's. The blocks come out smooth enough so I also ditched the floor wax.
THe only bad thing I have to say about it vs. Excalibur is it definitely isn't as strong. After letting both casts dry a few days, I used the dreaded throw it into the cement floor as hard as I can testing method, and the Excalibur blocks would chip slightly, but the Merlin's would basically shatter. But, given that if you drop your wizards tower 4 feet onto a concrete floor, I doubt it will matter what its cast out of, this is something I can live with given the other advantages. OH, and it mixes *thin*. Make darn sure your work surface is level, and keep a bit back in the mixing cup for after you vibrate the mold, it sloshes out a bit during that.
Overall tho, I'm switching for certain....at least until the next great plaster comes out .
Also: I doubt anyone who reads the board needs another endorsement, but Cindy at Clint sales couldn't have been nicer. They don't take credit cards is about the only drawback (I used pay pal); but she answered any and all of my questions about the plaster, didn't stick me that much for shipping (its a 50# box for gosh sakes, you should have seen the look on my delivery guys face...) and I'm pretty darn sure it shipped the same day I ordered it, because it only took two days to make it to Iowa using standard shipping. I'll be ordering from them again.