core material

[rcoy]

ok. im a long time lurker. i think im finally going to get started on rebuilding me 73-74 22.2.  ive been all over the net reading build threads from all over. the thought of rebuilding a classic beaut to my liking is just an awesome idea and would give me a great sense of pride. so with every build i skim through ive notice the difference is core material. im sure this is covered somewhere over the net but i would like to get the input from aqua sport owners.  composite vs kiln dried treated wood.  i know the big difference is weight. is it really that big of a difference? will i suffer in draft? i read through boatbuilding central build thread of his 22.2 flat back and somewhere in the thread he said if he was going to keep the boat for him self he would have done it all in wood. which make me feel like composite is a "gimmick."   if im beating a dead horse here, just point me to the dead horse.  

   also looking for a cheap covering/car port to make so i could work under.   thanks

[seabob4]

Properly installed wood coring will do you just fine.  After all, they've been building boats out of wood for quite some time now...haven't they?

Myself, being in the OEM business for, oh, say the last 20 years, well, I'm a composite guy.  Because let's face it, today's builders use composites!  Coosa, Nidacore, divinylcell, coremat, klegecell, been there, done that.  All excellent materials.  The 2 distinct advantages they have over wood...less weight, no rot.  And, in some cases, increased strength.

Frankly, I think there is TOO much discussion in regards to this.  Use your head, use what your budget allows, do the job right, and your work and your boat will reward you...  

[RickK]

Having done a little rebuilding on my 170 15 years ago and using 5/8" ply to replace the sole I can say it lasted quite a while and when there was degeneration of the wood I was a little surprised. I have an idea why it happened but when I cut the flooring out I saw that 95% of it was just the way I installed it long ago - still looked new.
Now I tore into the boat and am doing it from the hull up and think I'm going to go Plascore for the sole - could easily go with 5/8" ply again but think I'll go the composite route this time. I'm bringing this baby into the 21st century. The transom will be wood, backing in the console and the original casting deck but otherwise wood free.

[Capt Matt]

Personally I think if you are going to put the time, money and love into a total rebuild why not go with a material that will not ever rot, is lighter and stronger than wood. Rebuilding is miserable work at times and the thought of having to redo it 5-10yrs down the line because screw holes or a deck plate that was just not sealed right was not a option.
To each his own though
Capt Matt

[gran398]

Personally I think if you are going to put the time, money and love into a total rebuild why not go with a material that will not ever rot, is lighter and stronger than wood. Rebuilding is miserable work at times and the thought of having to redo it 5-10yrs down the line because screw holes or a deck plate that was just not sealed right was not a option.
To each his own though
Capt Matt

A correct rebuild is expensive. The cost difference between wood and synthetic isn't much after all of the money has been spent.

[aqua1967]

Gran is correct, I've been doing a lot of research and found a boats builder forum they say it's some were between $200 to $400 difference in saving, plywood has been used for many years and it's an excellent core but because it's an organic material water will rot it overtime, they say eventually will, oh they said "marine plywood" not home depot grade.
I just bought a 1985   222CCP  will use nida-core on floor and rear gunnel, will raise the transom and will use pourable nida-bond.
Suggest go to their website and if this is your choice, follow their spec's
Also look into Carbon Bond, similar product as nida. but seem a few buck lower,,,
Also look into.
Coosa Board
Airex

[kaptainkoz]

I researched them all as well and I am going with plywood. I love the composites and my 1st choice would have been coosa. Why I'm choosing plywood is cost for one. Coosa is almost $300 a board vs. $75 and I need 4 boards. A prior poster is correct that what's another $800 if you want to do it right. My biggest factor for going with ply is screw retention. It takes special steps to get a screw mounted in Nidacore and they don't hold as well in coosa as they do in plywood. Center consoles and tee tops need a bomber hold to stay put. When you do the composites you have to plan ahead on how you are going to mount the big stuff. If cost weren't a factor coosa would be a very tough debate for me. For now it's tried and true marine ply. Most failures I've seen are around cut outs and screw holes. If you address anywhere and everywhere you penetrate the fiberglass you might eliminate the main cause of core erosion.
Not to get off topic but for me, composite transoms are a no brainer.  There are too many holes associated with a transom to think you are going to keep that core dry for long. I am pouring with sea cast. Good luck!

[Shine]

i know the big difference is weight. is it really that big of a difference? will i suffer in draft? i read through boatbuilding central build thread of his 22.2 flat back and somewhere in the thread he said if he was going to keep the boat for him self he would have done it all in wood. which make me feel like composite is a "gimmick."   if im beating a dead horse here, just point me to the dead horse. 

That was me    and yes I would probably use plywood if i were to do another aquasport for myself. In fact, a couple years after that aquasport I did a seacraft (for myself to keep) and did use plywood coring.  All holes were drilled, filled, re-drilled so there was no chance of moisture getting to wood.

I am about to get started on a new rebuild and I will probably go back to composite for this one, mainly for logistics, but also for re-sale.  You will almost certainly get every penny more you spend in a composite core vs. ply when it comes time for re-sale

The weight difference is only going to be a meaningful savings if you use some of the lighter cores (PVC foam or honeycomb).  Using the heavier polyurethane foam boards (Coosa, Penske, etc) does not really save much weight over marine plywood core.

I highly suggest avoiding screws to mount the console.  You can glass it down and avoid them altogether.  If you must use screws then drill/fill/redrill so that the screws are going into epoxy putty "plugs", not into the wood.  Its more work, but its not hard.  Drill a hole at least double the diameter of the fastener you will use, fill the hole with epoxy putty, sand flush, re-drill a small pilot hole for your fastener.