CT-1 adhesive

[Alan]

CT-1 is a general purpose adhesive in 310ml cartridges and available from builders merchants. I used it in Four Candles to hold plywood bulkheads into the grp hull and it worked really well. It was recently reviewed favourably in a recent Watercraft magazine, and I just had the idea of using it to laminate the teak stringers of my SOF boat as it is so easy and mess free to use.

I took a few scraps of the 25mm x 8mm stringers and glued up a couple of lap joints about 90mm long to do a quick test. One joint was with the wood in it's natural state and the other was "degreased" using the CT-1 manufacturers proprietary solvent. The solvent didn't seem to evaporate despite rubbing most of it away with tissue to remove the oil in the wood, and despite being sold as ideal for preparing surfaces for CT-1, including wood. About 20 hrs later, after a room temp. cure I tried to pull them apart. Neither joint could be pulled apart by "peeling"; it was obvious that the wood would break before the glue, which is very rubbery. There was no possibility of pulling it apart by tensioning along the two bits of wood (shear). But by placing the joint over my knee and pulling really hard I was able to break the joint which was cleaned with solvent. This was also in "shear" mode but the joint was being greatly stressed at each end, and not at all in the middle (until the ends gave way).





I think this is good enough for laminating the stringers especially as I've thought of a way of doing it on the boat, in their intended shape. Makes a good gasket too.