Here is the info on Urethane Structural Adhesives. I included a link to their website so you could look at their products and there is an interesting article concerning their strength at- http://www.abrn.com/archives/0399tech.htm.

"The procedure that we would use to repair a kayak in an emergency is the SMC STRUCTURAL REPAIR (non cosmetic area). The difference is that we would only need to do procedure 1 and 4. 2 is only required to achieve a good finish on the outside of the boat, which we can do at home, and three is a 'what not to do'. "

The products will do so many things that it is impossible to explain them all. If you try urethanes I think that you will find that they are unbeatable in many applications.

I hope that some will find this information useful. Ian

SMC REPAIR & BONDING PROCEDURE 4050, 4154, 4186 (4176), 4188 (4179), 4056, 4058, 4904, 4905 SMC STRUCTURAL REPAIR (cosmetic area) 1. Sand off the back side of the repair. 2. Grind out any loose SMC material on the front side and feather back leaving the gel-coat intact on the outer part of the featheredge. 3. Do not clean the repair area with any liquid, wipe off with a dry rag. 4. Using either a piece of SMC material or 4921 Or 4922 light-cure laminate, reinforce the repair area by gluing the patch on the backside with 4050 or equivalent Duramix glue, depending on the work time required. Be sure that no glue shows through to the front side. 5. Fill the front side of the damaged area with 4056 High Density Filler to the thickness or more of the original SMC panel. Allow the filler to completely cure. 6. Allow filler to cure for approximately 15 minutes and sand.

SMC STRUCTURAL REPAIR (non-cosmetic area) 1. Sand off the back side of the repair. 2. Grind out any loose SMC material on the front side and feather back leaving the gel-coat intact on the outer part of the featheredge. 3. Do not clean the repair area with any liquid, wipe off with a dry rag. 4. Re-enforce the backside with 4050 SMC fast set adhesive using 4904 or 4905 re-enforcement. 5. Using 4058 utethane filler, fill the front side of the repair area. Allow to dry 15 - 30 minutes. 6. Finish sand and refinish as per paint manufacturers specifications.

SMC STRUCTURAL REPAIR (cosmetic area) OPTIONAL REPAIR 7. Sand off the back side of the repair. 8. Grind out any loose SMC material on the front side and feather back leaving the gel-coat intact on the outer part of the featheredge. 9. Do not clean the repair area with any liquid, wipe off with a dry rag. 10. Place masking tape over the backside of the opening of the repair. 11. Fill the front side of the damaged area with 4056 High Density Filler to the thickness or more of the original SMC panel. Allow the filler to completely cure. 12. Remove the masking tape from the backside and re-enforce the damaged area with 4050 SMC backer adhesive imbedded in 4904 or 4905. 13. Sand off the front side and refinish according to your paint manufacturers specifications.