Check this adhesive out.
StarBoard can not be glued using standard adhesives. Products like 3M's 5200 work well as a water sealing caulk but will not adhere StarBoard to itself or other materials in a permanent bond.
It is preferable to mechanically fasten StarBoard but when an adhesive is necessary you can use a product called #7540-AB or 3M's Scotch-Weld DP-8005. We do not represent these products, make any claims about their abilities or except liability for them. We have however used them with success and had good response from others who have used them.
#7540-AB is sold by Adhesive Methods and Technologies, Memphis TN Phone 901-367-1335 Fax 901 367-1308. Ask for Larry Doring.
How Should StarBoard® Surfaces be Prepared?
The surfaces to be bonded should be lightly abraded with a medium grit sandpaper before cleaning the surfaces with acetone, Toluene, or alcohol.
StarBoard should then be flame-treated on the entire surface to be bonded with a propane torch. Pass the flame over the surface at a distance of approximately 1" to 2" so that the blue (oxidizing) portion of the flame is touching the surface of the StarBoard at a rate of approximately 12" per 3 seconds.
There should be no scorching or visible difference in the surface appearance when properly treated. Ideally, the surface prep should be performed within one hour of the bonding process. Make sure to flame treat in a safe well ventilated area.
How Should Other Marine Surfaces be Prepared?
When bonding plywood, insure that the surface is dry and clean. No other surface prep is necessary.
When bonding aluminum, steel, and FRP, lightly abrade the surface with a medium grit sandpaper. Clean the surface with acetone, mineral spirits or alcohol. For the best results with aluminum, surface oxidation should be removed and an appropriate aluminum primer should be used to prevent further surface oxidation.
How is the adhesive applied?
#7540-AB is a complete adhesive system that includes a two part adhesive cartridge, a static mixer attachment for equal blending of the adhesive and a dispensing gun. Adhesive is dispensed by installing the static mixer on to the adhesive cartridge, cutting the tip of the mixer for desired bead size and pumping until the mixing chamber is full.
Discard the initial amount of adhesive that is not fully mixed to a consistent ivory color. Apply adhesive equally to each surface to be bonded with an even coat of approximately 8-12 mils. The adhesive should then be spread over the surface with a putty knife or metal spatula. Join the two surfaces, securing with a spring clamp or similar "C" clamp for proper pressure (2-4 PSI) for a tight bond. Excessive pressure will squeeze adhesive out of the bonding area. Optimum adhesive thickness is 15-20 mils when cured.
Working Time : Approximately ten minutes in average temp. of 65°-100° F.
Clamp Time : Approximately six hours with a cure time of 24 hours.
Coverage : Approximate coverage is one sq. ft. with a 20 mil thickness per 50 ML cartridge.
Cured Bond Line : Application of adhesive at 8-12 mils per side, curing to a 15-20 mils thickness.
So I called Adhesive Methods and Technologies, and talked to Larry. They sell the stuff in 50mL double-barrel tubes for $10 each or $8.75 each if you buy a case of 12. You can get an adapter for a standard caulk gun for $5 extra and extra nozzles are $0.75 each (which allow you to use the same tube more than one time - nice.