Since I'm kind of late to the C/L world I never have used SIGment or Ambroid that so many of you talk about. When and where would you have used these adhesives? (I use DUCO for cloth hinges; CA and Titebond for most everything else)
As noted above, Duco/SIGMENT/UHU Hart, are all the same thing or at least very close. Ambroid and apparently Dave's fabric cement is the same idea with slightly different contents.
These are what are called "model cements" and go back to the early 1900s. Ambroid originally started out as a coating use to apply and seal canvas on the bottom of canoes. Duco and things like it were called "household cements". Recall that in this era, hide glue was pretty much all there was, so having an air-drying glue/cement was a bit of a new thing, They were/are basically some sort of plastic dissolved in some sort solvent, when the solvent evaporates it leaves the hard plastic behind. It's not a lot different from plastic model cement, different plastic (polystyrene) but again the same concept. It's also the same idea as nitrocellulose and butyrate lacquer, just thicker.
I one time found an old book from the 20's telling you how to make cheap glue by dissolving celluloid toothbrush handles in acetone as a alternative to that expensive pre-made Amber-Oid.
After they discovered balsa wood ,they also found that the household cements were great for holding together balsa, and reasonably fast-drying. They sand better than most of the alternatives, so there is still some use to them. Much later someone came up with water/casein-based white glue and still later aliphatic wood glue, and still later acrylic and cyanoacrylate adhesives which became common in the 70s when the Hunter brothers started marketing it to modelers.
Ambroid was for many, many years the gold standard of model adhesives, and probably would be still be my choice for gluing balsa if it was that or Duco/SIGMENT, etc. It's not nearly as strong or fast as any of the current alternatives. I use lots of cyanoacrylate (Zap thin CA and Hot Stuff "Super T" medium), some epoxy, and small amounts of aliphatic and only tiny bits of model cement. I have a little tube of UHU Hart in my toolbox for quickie repairs.
Brett
p.s. one of the big issues with model cement is that is shrinks a lot as it dries. This can cause all sorts of problems in both keeping your airplane straight, or the finish, because if you finish over it, all the seams sink in later and show the joint lines. You can use it to your advantage to patch holes in silkspan/dope and some other areas.
Ambroid was also notorious for leaving orange lines in your paint, since dope thinner is also Ambroid thinner, and it was tinted amber/orange. SIGMENT is at least clear so when it happens you can't see it.
Topic: Sig Mfg (Read 2160 times)
