Here We Go Again

[GradySailfish]

Strick, its great you just did that project because I have a hatch I need to build as well. The tank coffin lid on mine was warped and cracked....basically unsalvagable, so I had the idea of making my own.

Once my Grady is back in the water I'll start work on the SC again and thats one of the first projects I plan to tackle. My plan was basically the same as yours, but I was going to put some gelcoat in the mold before hand, but since I'll be painting the boat anyway, it doesn't really matter if I do that.

Can you explain how you got those edges so perfect? I know you used clay but can you be more specific? I saw somebody use bondo to create the rounded lip....do you think thats a good idea? Did you use MDF to lay up the tank lip?
Thanks in advance...your project is looking great.

BTW Otterlycool, this is Alex from Capt. Dan's Capt license class. Remember me? I'm rebuilding a 20 SC right now. Getting the topcap off was no problem...I undid all the screws holding the cap and hull together, cut the adhesive between the hull and cap, and after some persuasion utilizing crow bars she popped right off.

http://i37.photobucket.com/albums/e5...h/IM000954.jpg

That pic is kinda unclear but shows the cap pulled foward. I later got help from a couple guys and we lifted the cap off the boat, placed it on the ground and I recored the cap and put it back on......which required crow bars and jumping on the cap!

[Rich]

Strick,

why use the small plywood squares for coring? Why not just use one sheet? Will the small squares create a stiffer panel?

[strick]

Grady- I used some wax based modeling clay called Supersculpy. If you go back a page or two you will see a pic of it. I rolled it into long thin pieces and then pressed the pieces very firmly into the bottom edge around the preimeter of the mold. Then I took a plastic spoon and with very hard pressure ran the spoon several times over the clay keeping the same angle. For lay up I cut 4 small 1 inch squares of cloth and stuck a piece into each corner then I ran some 2" cloth tape around the edge of the mold. I should have taken a pic but did not.

Rich--> when I re did my hatches on my 23 they were all cored with the plywood squares and I thought that was kinda a weird way to core something. With the squares you don't have to worry about a single piece of wood being slightly warped. You get better surface contact with the squares and I do think it is stiffer because of the cabosil between the squares. Also you use less wood and you can cut up your scrap. There is only 1 layer of 1708 on the bottom of this hatch and I can jump up and down with no flex at all in the hatch.

strick

[Ed]

Rich-

Most production boat builders who build boats with wood cores, use the squares instead of single sheet. As Strick alluded to, the reason is that each little square will adhere better...much more so than one large piece. Another advantage is that if you fully encapsulate each piece in resin, you are less likely to have water creep through the entire coring causing it to rot as is commonly the case with a single piece of wood coring.

Finally, the little pieces...mean less wood is thrown out as scrap....which can add up to a lot if you are building a couple of thousand boats a year.

-Ed-

[Bigshrimpin]

Don't forget it's easy to store squares in a cardboard box and a hell of a lot easier to move a box of squares than a 4x8 sheet of plywood. I think the resin/cabosil grid prevents delamination and increases stiffness.

[hermco]

One of my first jobs in the marine industry at Sea Vee Boats Miami FL in the early 80s was reducing 4' x 8' plywood into 5" squares to feed the lamination dept. I was glad when they switched to Divinycell foam core!

[BigMike8o9]

I have seen triads used instead of squares because they contour better on surfaces that are not flat. Works good.