what is cdx ?

[deedee]

i have a couple of questions. i saw cdx and bc plywood in hd today which is better for the case of boat building?both about the same price. i asked the guy about a good exterior plywood or just exterior and all he could say was salt treated,salt treated, salt treated. if i were to use some good exterior in the boat where would it best be used? just for the molds,seats,buttblocks? i plan to use meranti on the sole and side panels but the rest i don't know. one last one ! why would i not be notified of replies in my email anymore, they just quit one day.

thanks
deedee

[DRW]

There is a ton of information about plywood in these forums, I would start by reading the FAQ (top left menu this page) and the Materials section of the How-to's & Tutorials.

This thread http://www.bateau2.com/modules.php?name ... sc&start=0 has some opinions also but I personally would avoid CDX altogether and if I were to use any treated wood it would have to be specified "for marine use".

All things considered the extra cost of good ply is offset by the savings in time and epoxy over cheaper grades.

About the reply notification go to your profile via the link at the top menu above this forum and check the always notify of replies option of it and make sure your email address is current in your profile also. You can change the preference for each post when you submit by checking the bottom box when you submit it.

[MikeS]

Deedee; CDX means an exterior (X) plywood with one C graded side and one D graded side, both of which are too rough for any use in a boat, having many exposed and unfilled knot holes. It is used primarily for roof decking and sub-siding on houses. BC is almost as bad but some people pick through the whole bunk and find some usable stuff. Get a price from Jacques on plywood as you might find that, even with shipping costs, he can beat some local prices. BTW, I have a son who is home based at Little Creek Amphib Base and he looked high and low in your area for marine ply; prices were outrageous considering all the boat and ship building going on in the area.

MikeS

[deedee]

you are not mistaken !! the price of fir , meranti and the rest is totally outrageous here in va. beach and surrounding areas . i only inquired with about four dealers and i hung up that idea. i have some birch plywood that i wanted to see if it was acceptable for use in the boats. it has equal laminations and no voids but...... it probably isn't the right glue. it is definitely rigid enough for quarter seats and the like but who knows. here it is either exterior plywood($15 for 1/4 ) or $40 or so for the fir.i thought that the hard part was buying all the resin ,fillers and supplies , i was wrong .

thanks for all the replies

deedee

[DrBones]

I'm making my console out of CDX. Yep, it's awfull looking stuff - But I sanded it down (one round of 80 grit w/Mr. Beltsander and one round of 100 grit w/Mr. Porter Cable)..and will wrap the exterior in 4oz FG cloth. I'll post a pic when I'm done. Looking nice so far.

What really suprised me was that I only found one 1/2" void in the edge after cutting up a whole 8' x 4' sheet of CDX. Lucky me. The knot holes I'm just going to fill w/wood flour where they bother me. I think a 1/2" sheet of 8' x 4' CDX was under $10 if I remember correctly.

[Doug]

IMHO this is why CDX is a waste of time and possibly $$$ . I built my console out of 1/4" meraniti, no rough sanding, no filling, no covering with FG cloth. Just one coat of epoxy to seal, two coats of primer, and topcoat.

[clearwater]

deedee- What are you building?
On a previous thread (http://www.bateau2.com/modules.php?name ... ic&t=2472I) was crying about the cost and availability of ply wood in my area (Northwest suburb of Chicago). I will be working on an OB15, and have found; thanks to Jacques, a nice happy-medium between cost and weight using ply from http://plywood.e-boat.net/index.php. Later, I will try to post the weight/cost comparisons at the thread that I came up with for my boat.

[Frenchpete]

D2,
Just to add my voice to the chorus: skip the CDX...if you think it looks bad on the outside, you should see the junk in the inner plys (I work at a plywood manufacturing facility). Like MikeS said, it is mainly used for roofing, possibly under siding also...just 'fogettaboudit'...spring for something better, you'll be glad you did in the long run.

Richard

[deedee]

thanks for all the insight on plywood . i went ahead and bought the meranti. happy ? i am ! i go to pick up the plywood today , just a couple of days after i ordered it. jacques does a great job matching or beating all the competition. thanks again for all the great service at bateau and boat builder central.

deedee