246 rebuild live from Delmarva!

[Callyb]

Rick, I am fairly certain that the wood will be the coring for the boxes.

Shore, How did the transom come out?

[4shore]

The wood is permanent. I know some on here are going to think that is a poor idea and the wood will rot but I guess we will see. I will hot coat all of the surfaces and the outside will get biax at the seams and at a minimum csm all over.  On the inside i want to add urethane foam panels for insulation but i am up in the air as to whether or not to lay glass on the wood and then foam or foam directly to the wood and then glass over.

My instinct is that even after hot coating the wood thats probably not enough moisture protection and the foam isn't designed to be a moisture barrier

[4shore]

Hey Cally, thanks for checking in. I had a bit of a setback with the transom not adhering correctly to the outer skin. I believe i didn't properly clamp it so i had to cut a bunch of it out and rebuild the outer skin. 1708x2 +1808. So the outer is done all i have to do is tab in the inside and do my lamination across the transom on the inside. Then i will be adding knees. I ran out of vinyl and had some poly laying around so i built these boxes.

[RickK]

The wood is permanent. I know some on here are going to think that is a poor idea and the wood will rot but I guess we will see. I will hot coat all of the surfaces and the outside will get biax at the seams and at a minimum csm all over.  On the inside i want to add urethane foam panels for insulation but i am up in the air as to whether or not to lay glass on the wood and then foam or foam directly to the wood and then glass over.

My instinct is that even after hot coating the wood thats probably not enough moisture protection and the foam isn't designed to be a moisture barrier

Ahhh, I see.  I don't think you'll get any nay sayers here as to what you use.  Wood has and is still being used in boats everyday.  As long as it is prepped/sealed properly it'll last decades.  We have rebuilds going on right now here that are using all kinds of different substrates.
I was going to go 5/8" ply for my sole but changed tracks at the 11th hour.  My console is mostly wood and my transom is wood.

[gran398]

We have one small triangular piece of plywood in ours. It is embedded under the casting deck. We took a look at grinding it out....but it was as shiny as a new penny. It had been there for 41 years, entombed in glass and resin.

41 years from now, Good Lord willing, it will still be there.

[Callyb]

The only thing I would advise, is to cover the plywood with at least 12 oz. cloth to keep it from checking (fir WILL check on you down the road), and some abrasion/puncture resistance. If you do that inside and out you will be golden.

If you just hot coat the wood and it inevitably checks on you, you will get moisture intrusion.  :ncool:

[4shore]

I've got some 1208 hanging around i will lam it inside and out, should be pretty strong.

[Callyb]

That will do the trick! :)

[kaptainkoz]

Pretty much the idea that goes with using wood in marine use is that it must be fully encapsulated from the elements to last. Once the fiberglass has a small breech water will soak the coring drop by drop.  Also 1208 (as with 1708 and 2408) has the bulk of the weight in a weave which if in Single layer could actually end up more porous than doing multi layers with a lesser weight. Sure it's strong as heck but I don't think strength is the issue as those boxes look stout. If it were me I would think about a few layers at a lighter weight glass to ensure there is enough overlap of fibers and weaves to insure water tightness.

1208 is good stuff but does not like right angles. It doesn't bend well at sharp 90 degrees as most fiberglass doesn't. I see that you have rounded the vertical edges but my concern shifts to the upper and lower horizontal edges. Those may be really tough to get the glass to conform to especially in a heavy weight like 1208. You may have to go with multi layers of a lightweight chopped strand matt to get those covered properly, at least for maybe the first few coats until a slight rounding occurs.

In any event, what you are planning to do is possible but you will need careful glass work to skin them properly. That's part of the reason why so many guys on here resort to mold making as it produces a professional looking product that is well suited for the characteristics of fiberglass materials. Those pieces would come out awesome out of a mold. Sure it's more work up front to design and make the mold but it appears you have great wood working skills. A mold takes the hardest part out of the process which is manipulating the wet fiberglass. You do not have to be a good fiberglasser to fill a great mold. You can almost screw it up and still pop out a great piece from a good mold.
Just some food for thought. If your curious as to how to do what you are doing by mold, pm me and I'll clarify in greater depth.

[dburr]

Good point Steve about the weave.... The kayak and other stich and glue builders are adamant about filling the weave. If one layer of glass is all that is going down then as soon as that layer is green (to keep the glass from floating) another layer of resin is squeegied down, followed by a third once the second layer is green. In Shores case the inside is going to be covered with foam so to speed up filling the layers he could get a bit of his favorite, non wicking filling agent and save a layer and a bit of weight.

If the surface is going to be bright finished then an extra coat for a total of 4 unthined coats has worked the best for me. As for pouring foam on wet glass, some destrctive tests (not the most scientific methods employed) showed me that wet on wet has no noticeable adhesion difference when put down on a properly prepared surface but makes a big mess.. If you go over epoxy and you did not get rid of the blush, nothing is going to stick to it other then the marshmallow fluff that your kid just spilled on it.    Otherwise the 2 part urethane foam will stick well.

[Callyb]

I'm going to have to stand my ground on this onnt ways to go about this, but he has the 1208...and the two points here are 1) keep the wood from checking (with the least amount of weight), 2) These boxes are to be sat on. They need to be as strong as the rest of the boat. Would you take a chance (on you boat) of having the seams cracking or worse, catastrophic failure because there isn't enough glass on the box to transfer to loads to the boat and away from the gaps where the panels meet in the core? This isn't a production environment. We can use superior materials to reduce weight, otherwise I would say bust out the chop gun and coat the hell ot of it.

As far as the weave goes... I apologize in advance, but that is ridiculous... You need to prime the wood anyway, and you need to fair everything after the fact. If you have voids in your weave because of a dry laminate, I'm thinking you are going to have worse problems than rotting wood down the road.

[dburr]

I'm going to have to stand my ground on this onnt ways to go about this,

As far as the weave goes... I apologize in advance, but that is ridiculous... You need to prime the wood anyway, and you need to fair everything after the fact. If you have voids in your weave because of a dry laminate, I'm thinking you are going to have worse problems than rotting wood down the road.

1. This site is about advice, guidance, help and moral support.  When advice or guidance is given in the past the poster has made certain that his/her guidance is of sound experience or researchable fact.

2. Take a look at CLC light-craft, ANY of the over 250 issues of WoodenBoat (been in circulation for over 20 years) and you will see the SAME info about filling the weave.

Admin Edited

[Callyb]

Dave, I'm thinking that you may have misunderstood what I was saying. Please re-read what I was saying. I agree that the weave will be filled, but I am saying that cautioning about it is the ridiculous part. It gets filled by virtue of finishing the part. Therefore If you have water penetration through the weave of your cloth after you are done with the lamination, you have a dry lamination, which means you have bigger problems than rotted core material down the road.
Admin Edited

[gran398]

Alrighty brothers, gonna use my PR appointment here.

This place has never been THT, and never will. We pride ourselves on a club atmosphere.

In many instances, as we have seen, we have lively discussion....but never arguments.

I don't see this as anything more than discussion, maybe with a little cayenne

Many valid points regarding methods...guess we can agree it got to this point mainly on the topic of radius adhesion.

Lets get back to that....thanks

[kaptainkoz]

the beauty of this site is the sharing of ideas from many different walks and backgrounds. We post ideas and questions with the comfort that we will get a variation of responses both amateur and pro to help us get where we want to be. We also trust there will be checks and balances that if a suggestion is way off, the masses will correct it. I have a few years experiences in glass work and I let it be know often that I am a novice to avoid a blind leading the blind scenario. Alot of what I have done is first run. I share the similar experiences of many attempting activities beyond my experiences and reporting the good and bad from a novice perspective figuring many of us may hit the same learning curve bumps in the road. I then hope that those in the industry and the experienced will chime in and say well thats close... but this may be better. Fiberglass has a complex learing curve which is best learned through experience.
In the instance of the sharing of ideas i see on this post, everyone is right but from their own perspectives. I for one have seen newly poured foam ooze from the weave of my factory stringers on my 246CCP. I was surprised to think this was even possible as the layup process seems so rich and thick. I have also experienced that resin, although thick and sticky, is somewhat brittle when thin and not attached to fiberglass fibers. I can see how someone with alot of experience in a professional setting could find it incorrect to say that a single layer of fiberglass could be porous. However in a strictly amateur, home garage setting attempted a hand full of times it could be possible. Its a crossroads of mindsets, but its also a great opportunity to share how to get the desired end result. We are all friends here. I appreciate all and every suggestion. It is up to the individual to decide which of those suggestions works best for them, good, better or best. I encourage all of us to keep posting and sharing and remain confident in your suggestion regardless if there is conflict or if your idea is checked a bit agrssively. Id rather someone post and get checked then to not have them post at all. That will only lead to a weakening of diversity for the site. I have no ownership or stake in the site other than a deep respect for what it has given me. It is up to the reader to choose which way to go with the information, it is up to the posters to try their best to information to the best of their experience, wether great or not so great. at the end of the day we are all friends here and I thank you all, always!!!