that I need to make into a double arch bridge, so the face castings will be joined at their edges to make one long bridge side that will look more like this:
Then, I need to glue a piece of 1x4 pine on which to lay the track and roadbed and to give structural integrity to the bridge – so both sides of the bridge will be glued to the pine which will be the top deck. The top deck in other words will be plaster at the sides and wood in the center but flat and even
The pine in turn will extend beyond the bridge to meet up with the elevated subroadbed of the rest of the layout so the track will be smooth and unbroken across the top of the bridge and beyond. In a sense the bridge will almost be supported from above rather than holding up the track.
Am I making myself clear at all here?
What glue works for you when gluing plaster to plaster, and plaster to wood? I am thinking Walthers Goo or Woodland Scenics Hobby Tack but am open to other suggestions. The plaster that Monroe Models uses does not seem to be hydrocal if that makes a difference. They call it high density casting gypsum. For all I know maybe that is the nontrade name for hydrocal.
I’m not familiar with the brand you have, but I have used latex adhesive caulking compound to fasten rock castings and tunnel portals together and to the layout.
White Elmer’s glue or Titebond yellow carpenter’s glue. These glues are water based & will penetrate the plaster & make a strong joint. Hobby tac will not penetrate & never really hardens. Goo also wont penetrate or be as strong as the water base glues. Good luck. Jerry
Caulk, more plaster, hydrocal, sculptamold, gorilla glue, MEK (at least, I glued a ceramic article back together with it and that was 20 years ago…plaster may be too porous), Goop, CA…
I sometimes need to glue plaster castings to styrene backing. For that, I use (smelly) silicone adhesive. You don’t want it anywhere on the surface, though, because it’s completely un-paintable.
For the butt-end joints, I’d suggest some sort of backing (wood, styrene, whatever) so that you can glue the backs of the two adjoining pieces on to the backing rather than trying to get the butt-ends to stay together. Then you can fill the face cracks with a bit of plaster after the whole thing is together, before you paint it.
Agreed. Apply a bit of water to one of the surfaces to be bonded, a lick of the Gorilla Glue to the other, and then leave it pressed together for about two hours to set up with a strong bond. If you gob on too much glue, it will foam out of the edges of the bonding perimeter, harden to an amber crust, and be a royal pain to clean up afterwards.
I always use “Tacky Glue” by Alene’s for projects like you’re describing. It comes in 4oz. squeeze bottles for around 79 cents on sale. It’s much thicker than Elmer’s and holds tight. Best of all, there is no smell.
