Types of plywood

[glennk]

Doing some off season recoring and transom work and I'm wondering what is the most effective., but cost effecive grade of wood for coring.

I'm going to be enclosing the coring in epoxy fiberglass so I don't think maring grade is really needed. Is CDX usable if I fill any major holes first and sand smooth, or is it just easier to get better wood up front and not mess with trying to clean it up? If so, what am I looking for A, B or C grade?

Also, is there a cheap but sturdy manmade alternative to star board?

Thanks.

-glenn

[adam aunins]

I see this company's adds in the back of Good Old Boat magazine They might be able to help out. Can't hurt. www.fiberglasssuply.com or call at 509-493-3464 [/url]

[DS 1858]

I would rec using MDO for transom work. Softwood plys are too soft and your gudgen bolts will sink into the softwood over time, even with layer of glass on top. There's a lot of load there on windy days and beachings. The MDO is waterproof also so if a leak into the core happens over time, did on mine, you'll be OK.

[swiftsail]

If you are worried about sinking into the core, which I would with any type of core with gudgeon bolts. You should pre-drill with an oversized drill and then fill with an apoxy resin and high density filler mix and then drill your bolt holes. That way you are compressing the filler not the core. Make sure you put washers on the inside to carry the load beyond the apoxy fill.

Steve

[Adrift]

Marine ply not only uses waterproof glue, it is a higher quality material. Harder wood, fewer voids, solid (or fewer pieces) on the inner plys, and if I recall correctly at least B surfaces. If a job is worth doing, it is worth doing right. Please don't use plain old plywood...

What Steve (swiftsail) suggests about overdrilling should be done on any hole made through cored material if you really care about your boat.