New 1996 Grady White Islander 268 with twin 200 V6 Mercs

[ScottyCee]

"ScottyCee, What kind of foam is that?"

I bought a remnant at a local fiberglass surfboard (SIC) shop. I always wondered why a surf shop was in my neighborhood with no waves and all, but they sure do have everything a person could want for glassing stuff.

It's 5/8" thick with a very fine resin / cloth layup on one side. SUPER strong. I don't need any reinforcement under the hatch now. (but I left it in)

 

[greauxpete]

Traweled on thickened (with west 403 adhesive filler) epoxy to the underside of the panel, then while it was wet, laid down some 1708 with the mat side facing up. Wetted it out and bonded the plywood core to the mat.

 

[family affair]

Nice work Pete!
I've seen a number of hatches redone and all of the original coring was small squares of wood. I see you used larger squares. Out of curiosity, why not one or two large pieces?

 

[greauxpete]

Full disclosure, this is my first hatch/panel repair. However, I'm an engineer and understand composites. My understanding on the use of smaller core elements is, larger core elements (pieces of plywood) tend to warp when subject to temperature fluctuations. The bond between the core and "skin" (fiberglass) is key. If the skin- to-core bond "slips" the strength of the laminate is greatly reduced. Smaller core elements limits this possibility of expansion and slip failure due to expansion.

Correlating the composite panel to a structural steel Ibeam, the outer fiberglass "skin" is similar to the flanges on the ibeam and the plywood "core" is similar to the web on an ibeam. If the connection of the flange to the web is lost, the flange will slide and the beam will be incapable of transmitting the tension and shear due to the moment induce by bending.

Think about bending a loose deck of cards in your hands. The layers of cards slide on top of each other.
Now envision the cards are glued together, the cards cease to slide and the bending resistance is increased greatly. (In other words, it's a helluva slot harder to bend the stack of cards if the are bonded together). In this scenario, the strength of the glue (or resin) between the cards resists shear and the tensile strength of outer layer of cards resists tension due to moment.

Additionally, scraps of plywood can be used to build out the core limiting waste and increasing profits.

 

[greauxpete]

First layer of 1708 glass, and bedded down the stiffeners:

 

[deepdesire]

Greauxpete congrats on the Islander. I have a 96 as well although mine has a single 300 Suzuki for power. Still have the original Florida Marine 134 gal tank from 96. I keep it filled and clean but I know I'm on borrowed time. Looks like yours could stand some wet sanding and polishing but from your photos looks like a great project. Lots of info and experience on this site. Good luck with your project!

 

[greauxpete]

Deepdesire, thanks for the comments. By the way, i see you are from Jersey.

I found a little history on this boat.
The original owner was Johnny Hector former running back for Texas AM and the NY Jets in the early 80s. He is from New Iberia (where he played in high school) just down the road from me.

 

[greauxpete]

Add corner fillets so the fiberglass cloth will bend around the 90 degree corner easier. Also adds strength to the stiffener.

Will probably go with a couple of layers of 1700 biaxial cloth versus 1708 with mat backing, so the cloth bends easier around the stiffeners.

 

[Hookup1]

Since you are using plywood you really have to protect the core. Most common way for water to get into core material is the screw holes that hold the hatch down. Drill out all the screw holes oversized from the underside, epoxy fill and re-drill from the top.

 

[greauxpete]

Thanks for the reccomendations Hookup.

I left a gap around the perimeter at all of the screw holes, which will eventually be filled with thickened epoxy with a peanut butter consistency (aka peanut butter). This will provide a hole surrounded by pure epoxy.

 

[greauxpete]

Glassed in the stiffeners with 1708..
It was tough getting all of the air out of the glass. Tried a fiberglass roller, paint brush, and spreader, but the glass seems to have a mind of its own.

 

[Hookup1]

Next time try a simple vacuum bagging process. Home Depot heavy duty plastic and some sticky tape from Fiberglast Corp. Use a refrigeration vacuum pump and disposable vinyl tubing. For tight corners a thinner plastic can be used. Squeezes everything together and pulls the air out. Use a slow hardener and be careful not to pull epoxy into the vacuum pump. Automotive clear spiral wrap will help provide a air gap on top of the part to get the air out.

Photo after first before vacuum bagging before glassing the top and vacuum bagging again. Put the hatch back down before taking pictures of the finished part!

 

[greauxpete]

Hookup1 - You've got skills..

 

[family affair]

Don't sweat it Pete. I'm confident the funk that will eventually grow in that compartment won't complain about having to look at your air voids!

 

[greauxpete]

family affair, LOL true...

 

[greauxpete]

We did some deep cleaning today:

 

[efx]

Looks good cleaned up! FYI I am about to replace that dead refrigerator with a set of drawers. That’s a common change. Also you have the same issue I have with the cloudy vinyl. The best product I have used so far is meguiars plast X. The vinyl reflects light on night runs and makes it difficult to see. It requires a lot of upkeep.

 

[greauxpete]

Thanks for the vinyl cleaner tip - I'll try that.
Do you know which model fridge will fit in this slot?
If have have pics of the drawers - please post if you can.

 

[Producer]

Glassed in the stiffeners with 1708..
It was tough getting all of the air out of the glass. Tried a fiberglass roller, paint brush, and spreader, but the glass seems to have a mind of its own.

Those are tight bends but next time flip the glass with Matt side down it bends Way easier and finishes off much smoother.. took me a lot of cussing before an old timer taught me the trick. Also wet the underside of the glass strips before laying it so it gets a solid soak and bends easier. It is nearly impossible for 1708 to get resin to soak through

 

[seasick]

Two methods to help the glass lay out correctly are:
Pre wet the cut sheets of 1708 with resin, laying the material on something that is not porous like a plastic sheet or panel. after pre-wetting, lay up the material and roll it out, using additional resin as needed.
The second 'trick' that works best for your type of stiffeners is to cut the material so that it goes up one side, over the top but short of the second fillet. Pre wet, and apply. Do the same for the opposite side, start on the flat, up the side, over the top and partially down the other side. Of course the pieces should overlap each other just not cover two fillets. On the ends, if the material bunches up, just cut slits and overlap the edges.