core thickness and other questions

[loop]

The boat is a 13'Allison. Original core thickness was 3/8" down the keel and up each side to the outermost strakes. Then went to 1/4" out to the chines. It has all been removed and sanded clean with 24grit. Will get 1 layer of 1.5oz mat before the core.
aside from the extra cost and the slight weight increase,is there any disadvantage to going with a
thicker core and is thicker always better?
Would 3/8" or even 1/2" thick throughout be complete overkill?
Would there be a significant increase in strength to make it worthwhile?
next question:
What would be a good alternative to the commercially available bedding compounds? They seem to only come in 5 gallon containers and I feel like it would be a big waste of money on a small scale project like this.

OK now get your popcorn ready:
epoxy or vinyl
core first or stringers

[Gorilla0178]

Oh man here we go again.....

A cored panel gets stronger the thicker it gets, double the thickness of a fiberglass panel with core and its 7 times stronger, quadruple it and its 37 times stronger than the original fiberglass panel with the same amount glass. (thats from nidacore's website) I would go with 1/2 inch, it'll just be that much better. As as far as bedding compound there are a bunch of manufactures that make them, there usually about the same, although they all claim to be better than one another. You can always bed it in wet glass, I would use 2, 1.5 oz mat wet out good and weighted down, if not any poly based bedding adhesive should be good. You should be able to get it in gallons. I would stick to either poly or vinyl, unless you really want to use epoxy, it is better, but it costs more and shouldnt be used with chopped mat. Look up fiberglass coatings inc, they usually have a good amount of stuff, and there brand is good.

[XstreamVking]

On my V-King, in an effort to save wt. I skipped the putty. I put dn some real wet 1.5 oz matt. Wet the backside of the 1/2" foam core and placed some thin ply over it with some bricks on it for weight. Over the core I put 1 layer of 1708 bi-axial. I used all vinylester resin for the rebuild. Been running it for a couple of years no problems. So, here's one way to do it........ I do not baby this boat, I jump waves and run it hard.....Floor and trans are made with penske board, densities of 12# and 26# respectively.

[Riverman]

On my V-King, in an effort to save wt. I skipped the putty. I put dn some real wet 1.5 oz matt

Bedding putty is very light, much lighter than mat and resin. ATC Corebond is about the same weight as lightweight body filler. Plus it is applied with a notched trowel so the quantity (thickness) is easily controlled.

[XstreamVking]

On mine I was going to put dn the 1.5oz matt anyway to replace what I had ground off, so.......No real need for the putty. You can use the putty too if you like. The core is not going anywhere. Also, the streams all came with balsa that was put dn into wet glass. Some lasted for 20+ yrs w/o failure...Rotten balsa was the only problem....As I said, just the way I have done mine. And, I know my boat see's more abuse than most, as I run mine in salt water that has waves and wakes from big boats. With a 3.0L EFI merc for power it tends to jump most waves/wakes it encounters. :D:D:D

[Matt Gent]

A cored panel gets stronger the thicker it gets, double the thickness of a fiberglass panel with core and its 7 times stronger, quadruple it and its 37 times stronger than the original fiberglass panel with the same amount glass. (thats from nidacore's website)

Stiffness, not strength.

I would just use 1/2" all over.

[Alan Power]

Stiffness, not strength.

I would just use 1/2" all over.

:iagree::thumbsup::thumbsup::thumbsup::thumbsup:

[David]

1/2" on a 13' boat? How do you plan on using it?

[hydroholic]

I would go with the 1/2" as well and would use the corebond to set the core in. As Riverman said its light ,strong and you can controll the thickness easier due to using the notched trile.Plus it adheres realy well.

[Matt Gent]

I'm using 1/2" on my 14' Hydrostream. Thickened epoxy, laid on top of wet 1708 with a notched trowel, then bed in the core (Corecell A500) and bag it down. The core is perforated to allow any trapped air to escape, leaving a bunch of epoxy columns to indicate it spread evenly. Hand layup of 45/45 biax on top after the core is set.

There is minimal weight penalty to 1/2" vs. thinner core, it is more stiff, and the material is readily available.