Repairing rotten core in Glass Tech deck hatches

[In Memory of Vicroy]

Well, since this site is all about helping each other, this will detail how I'm repairing my deck hatches that were cored with end grain balsa. The problem: my aftermarket Glass Tech fibergalss deck was installed in the early 90's shortly before I became the Steward of AJ. There are 6 hatches, all heavy glass on the top and sides, and cored with blasa. The glass on the underside is very thin, and the gasketing Glass Tech used was not so good and came off over the years......Through my own neglect, the gasketing went away and the hatches rattled on the gutters to the point that the glass on the underside got broken thru and water got into the balsa----rot and ruin on the order of 3 to 6 inches from the edges.

Probably not a strength issue, the glass top and sides is plenty thick, but just not something you want to pass on to the next generation of Stewards of The Best Boat Ever Built.

The fix: First, call Capt. Patrick, the glass guru of all time. Describe the problem (actually, he reminded me he'd seen it at one of the UVIs). He detailed how to do it to a guy that has not mixed resin in 30 years. And Terry Frank kindly sent me the new gasketing material.

So here is how it went......first, bring one hatch home from the camp and let it dry in the shop a/c for long enough to get most of the water out of the cored balsa mush. Next, take a small chisel and dig out the rotten stuff and break the thin glass over the voids so you can get to them..keep the shop vac handy.....let dry some more. Tried a heat gun but it almost burned down the shop...let dry a/c air do it, remember, time, patience and money...

After you have dug out all the rotten stuff, get some West System epoxy (105) and the very slow hardener (209), and buy the pumps, they are great for mixing. Then go to the garden center and buy a bag of Vermiculite....yep, that is what Patrick said. Pot plant stuff. I told my yardman (former driver, post Snow) to get me some for fiberglass work and he thought I was crazy. Anyway Vermiculite is mica that has been expanded in a furnace, think of it as mineral popcorn....lotta volume, no weight.

Mix up your 105 West resin with the 209 sloooooow hardener and then put hand fulls of Vermiculite in and mix and add till its as thick as you can get it with all the Vermiculite paticles wet all over...it is very coarse....then spoon or slop it in your voids, poke it around with a paint stirring stick or popsicle stick, tamp it down and let it kick....in a/c with the super slow hardener, it does not kick for at least an hour. Let it set up overnight. I found a trick to find out when its done - your infrared heat gun.....shoot the installed epoxy and vermiculite and when its the same temp and everything else its done. Took mine overnight to come to the same temp.

Then sand the Vermiculite with a 4" side grinder with about 80 grit, does great, makes a lot of dust so do it outdoors.

Next step (per Patrick) is to mix up a little epoxy and the micro ballooons, West is called Micro Lite (#410) to peanut butter consistency and trowel it over the sanded Vermiculite, and it comes out smooth as silk....let it set up overnight then sand with a palm sander and you are ready to paint for looks and glue on the rubber gasket.

Again, thank you Ole Fart for taking the time to tell a glass greenhorn how to do it....turns out its silly simple if you have the right stuff and the right guru...

Will bring the rest of the hatches home this weekend and do them, a very satisfying way to spend time. Lot more fun than chasing crooked bankers like in my prior life.

UV

[CaptPatrick]

Tio Veeek,

Glad ya' had fun playin' with my trail mix mud! Works well for vertical surfaces if you add a healthy amount of Cabosil to make the mix thixotropic, (won't run or sag). Can also be used with polyester resin when adhesion isn't an issue... Great for coring or surface reinforcement on the back side of molds. Very little shrinkage, very light weight for the volume.

Br,

Patrick

[In Memory of Vicroy]

Yeah Patrick, zero shrinkage on the Vermiculite mix, neat stuff, and really sands out great with a side grinder.....don't even think about hand sanding it, that mica don't cooperate unless power and an open grit is applied.

Per your advice I mixed the micro lite and epoxy a little thinner than peanut butter and it worked great, filled all the little voids in the vermiculite surface...its kicking now. I guess my adversion to doing glass work has always been my inability to mix the resin and hardener to the correct ratio, resulting in too quick a set or one that never really sets up. the West pumps take the guesswork out and have given me confidence to just mix it and go. Next time I'll probably go with the slow vs. the extra slow hardener since I'm working in a/c, but on the other hand, what's time to a hog?

Thanks again, you the MAN!!!!

UV
a/k/a Tio Veeeeek

[Bruce]

Only in the last few years has Glastech gone with all composite materials.

[RussP]

Linda & I repaired our hatches last year. I also glued in drains so water doesn't sit in the gutters which is one of the design faults of the old decks.

RussP

[In Memory of Vicroy]

Bruce, yeah, they now use composites, but I have wet balsa, working thru it.

Russ, my Glasstech decks have big holes in the 4 corners of the hatch gutters, so water does not stand in there, but on the other hand, that big ole pine tree that is next to AJ's dock plugs the drain holes with pine straw all the time. Anyway, I'm on the way to water tight deck hatches...time, patience, & money works all the time. And nowdays ole Tio Veeeek has a lot of time on his hands. Not a bad thing, just kicking back and saying, F**K IT, I done my time........

UV
Proud member of both the Mean Team and His Timmy-ness's tip toe thru the tulips people. Or was that someone else?

[Bruce]

Vic,
Nice to get a parole from the daily grind of life.

Enjoy it.

[In Memory of Vicroy]

Bruce, thanks, but it's not a parole, just getting out of jail on time. Like I told you guys a while ago, when God put His hand on my shoulder that Friday nite in the Atlanta airport back in March, I knew it was my time to go to the house.

UV

[JGomber]

While repairing the ply deck core of my Hunter, (yeah, got a blow boat, too. It helps me set up drifts better with the B31 when fishing) I found that spraying some alcohol on the wet core sped up the drying. Alc is hydrophyllic and sucks up some of the water in the core. This mix evaporates faster than water alone.
Hair dryer aimed at the wet core for an hour or so will also speed up dry time. Cooler than a true heat gun so less danger of heat damage.
An orbital sander head (not the sanding side) placed against the BOTTOM of your flat workpiece can vibrate the epoxy mix into all the crevices and vent out any bubbles.
You really didn't mean "pot plant" mix, did you? Could explain your laid back attitude.

[IRGuy]

Jerry...

Alcohol is sort of a generic term with many possibilities..

I use acetone in the same way you use alcohol.. but be careful of the external heating.. acetone, and many "alcohols" are extremely flammable, especially their vapors!

[JGomber]

Maybe I should have pointed out that these are individual tips and not to be combined!?
At least alcohol can be extinguished with water. Volatile solvents are another matter entirely, each with their own dangers.

[capy]

While repairing the ply deck core of my Hunter, (yeah, got a blow boat, too. It helps me set up drifts better with the B31 when fishing) I found that spraying some alcohol on the wet core sped up the drying. Alc is hydrophyllic and sucks up some of the water in the core. This mix evaporates faster than water alone.
Hair dryer aimed at the wet core for an hour or so will also speed up dry time. Cooler than a true heat gun so less danger of heat damage.
An orbital sander head (not the sanding side) placed against the BOTTOM of your flat workpiece can vibrate the epoxy mix into all the crevices and vent out any bubbles.
You really didn't mean "pot plant" mix, did you? Could explain your laid back attitude.

I think he means "potted plant" I don't think UV is on the reefer....

[AndreF]

For the sake of efficiency, Southerners refer to all plants in pots as pot plants. The saying "potted plants" brings visions of men & boys with lace on their drawers.

[Rawleigh]

No wonder he is enjoying retirement so much!!

[In Memory of Vicroy]

Well, just sanded out the microlite with a palm sander and as Capt. Patrick said, it sands like butter. Applied a coat of hi gloss white poly paint and it looks 10 times better than new. I am literally sitting here watching paint dry.......great sport.

UV

[capy]

For the sake of efficiency, Southerners refer to all plants in pots as pot plants. The saying "potted plants" brings visions of men & boys with lace on their drawers.

Those men and boys get married legally here in teddy kennedy land.........

[Bob S]

What did you use for the gasket material? My hatches don't have any and they rattle.

[In Memory of Vicroy]

Bob - I used a flat rubber material that's 2 & 3/4" wide and 1/16" thick. It's used for door gasketing on refrigerated doors....one of the Faithful kindly sent me some. Works perfect. Some of the other Faithful had some ideas on another thread.

Brought the other 5 hatches home and gonna tackle them today. The one I repaired last week was the worst rattle offender and now it's silent. BTW, the GlassTech deck actually has two lips, one about a half inch, then the gutter, then an interior lip.....using the 2-3/4" wide gasket material and attaching it to the underside of the hatch flush with the outside of the hatch, it contacts the half inch lip and virtually makes the hatches waterproof. I used contact cement, roughed up the rubber with some 80 grit, let both surfaces dry, then put some wax paper on the hatch, pressed down one end and slowly pulled the wax paper as I was attaching the rubber - worked great.

UV