My in floor hatch molds step by step by Kaptain Koz

[kaptainkoz]

I laid the next layer today which is 2408 biaxial. I also cut a piece of 2408 the size of the plywood stiffener and laid that under the plywood a bit on the wet side and sandwiched it all together. There is no resin on the top of the plywood just yet, and whatever is on the sides is just from brushing the excess resin that squeezed out under pressure. I even shimmed the work table level so the wet pieces wouldn't want to slide towards the pitch just to be safe... like I said I don't want to make these a 3rd time!!!







After I placed the batteries down I went around with the brush to smooth out any resin that squeezed out. Basically you want it as flat and smooth as can be for the following layers. I will not even think of touching these for at least 48 hours. After that a final layer of 2408 and I think I am done providing they are of an acceptable thickness to seal the gasket against the frame. If they aren't I can add more layers to improve my seal, or im thinking I will probably gel coat this side  as well so the hatches look neat when opened. I can build up thickness with gel coat too. I will see how it goes and decide on the fly.

[Callyb]

I am pretty excited to see you pop these out Steve. I don't think you will have any problems this time around. I would say you got it whooped!

Can't wait to see them popped out.

[kaptainkoz]

I am pretty excited to see you pop these out Steve. I don't think you will have any problems this time around. I would say you got it whooped!

Can't wait to see them popped out.

Thanks Carl. I am excited too but a bit gun shy after the last mess. Im sure they will be fine this time around. I look forward to getting the floor down before the fall.

[kaptainkoz]

I laid what could possibly be the final coat of 2408 biaxial today with unwaxed vinylester resin. I say it that way because I may have to add another layer or two for overall thickness, but if I dont then structurally they are strong enough at this point. I think they came out sweet over the plywood stiffeners. I used about 12 oz of resin per door for this coat. The 2408 lays down so nice, I love working with it. it doesn't like outside 90 degree bends but if you try to minimize the outside 90's you can lay this stuff down beautifully. My mold has inside 90's and it still won't tuck neatly into the corners thus I it's why I have all the layers under it to round the 90 a bit. 1708 has the same characteristics. Its in the biaxial weave that makes it pretty adaptable for its thickness.
As for the actual process, I wet the piece itself, then I wet the new layer of 2408 upside down (the chopped strand side) on a separate piece of plastic (the Callyb Method), then I lay the wet 2408 into the mold, stipple down with a brush from the middle to the edges, add resin as needed, then babysit the whole thing with a roller and a brush to make sure I don't get any surprise lifts or bubbles until it sets up a bit








I did get a little gassing lift on the wood indicative of the lighter patches. Note to self... I forgot to coat the plywood with resin and let it kick off before adding the 2408 biaxial. This would have allowed any reaction between the wood and the resin to happen without glass over it, allowing for a predictable resin to resin bond for the glass coat. It didn't happen along the beveled edges as most of that surface was resin coated from the the last layup. Im not worried as the stiffener is locked in and isn't going anywhere regardless of a little surface gassing.





I purposely cut the biaxial around the latch hump so to not add any thickness to it. It is coated with a layer of 3/4, then two layers of 1.5 oz chopped strand. That is more than sufficient to hold the shape of the latch hump/pocket without adding critical thickness there.




These will be weighed down with the batteries for at least 5 days as my schedule is crazy so be patient I will pop them out as soon as I can after that.

[RickK]

Good job Steve - patience grasshopper....

[CLM65]

These should come out great

[aquadaze]

So, Did they work out? Inquiring minds want to know.

[kaptainkoz]

I'm out of town. I'll pop them out Tuesday afternoon.

[kaptainkoz]

I popped them out a few days ago. No surprises this time





fits better right out of the mold than the last doors





I did some dremel grinding to fine tune the fit of the latch pocket. I went down to the gel coat in some spots.  I then covered the pocket with a think veil of 1.5 oz chopped strand just to hold the gel coat in place (where the "1" is).





I added the final full layer of 2408, and a perimeter strip of 2408. Both layers are stricly for build up to get the proper door thickness for proper clearance for the sealing gasket.





here you can see the 2408 perimeter strip




Here is the 5/8's Taco weatherstripping I am using







a few preliminary images of where the weatherstripping will sit





this is about where it will be stuck to the door. This photo illustrates how much the door shrank in the mold. You can see the black line between the door and the mold. Id say its about 1/16 of an inch.




Tomorrow I will fair where the weather stripping will adhere to the door for proper clearance and leveling, then I will gel coat the underside of the door.

[RickK]

Those are some beefy hatches - I don't think they will flex with anyone on them - nice job Steve  
I guess patience IS a virtue  :!:

I've been doing mundane stuff on mine, so nothing to report yet.

[kaptainkoz]

Thanks Rick. I look forward to your progress as well. They are definitely stout at 3/4 oz CSM, 1.5 oz CSM, 3 full layers of 2408, a layer of 2408 under the 3/4 inch stiffener, and a strip of 2408 around the perimeter, all drowned in vinylester resin. The latch pocket creates a weak spot though. I stood on the reject doors (without stiffeners) and they cracked right at the pocket as there is no lip there. it doesn't matter as the door will be resting on the gutter lip and not on the actual edges.
I think design 1.1 would have the gutter wide enough to clear the latch pocket so I wouldn't have to disturb the gutter lip and stress over making the profiles match up. I hope to never have to find out! These are a ridiculous amount of work to make. I cant wait to be done with them and get back to working on the hull.

[kaptainkoz]

I cleaned the excess glass up with a sand paper flap wheel on my 4 1/2 inch grinder. I set it in the frame to check the fit and grind down any high spots that I didnt like, concentrating pretty much only where the weatherstripping would go. I dont really care about how the under side of the door looks otherwise.

I shot it with Gel Coat. As a final coat for the project, I added TFA (tack free additive) which is basically wax. I also cut it about 10% with styrene to make it shoot easier out of the Preval.





I touched up a spot on the frame that I had to grind down to fit the door



I shot it all with a preval. I just held the cup under the sprayer avoiding the need to buy the kit with the glass jar. I only bought the refil. It shoots a fine mist which is perfect for touch ups. You will not get any real volume out of the preval and they are expensive at about $6 a can. Basically it took most of the can to shoot this small amount but its great for small touch ups and obviously it shoots gel coat if its thinned a bit. It comes with a strainer at the end of the pick up tube which has to be removed to shoot gel.

[kaptainkoz]

Spent a few hours creeping towards a 99% complete hatch. I used a stainless piano hinge with stainless T nuts




I had to grind down the T nuts to fit properly as they were too long and will not fit as a complete circle.







The T nuts ended up fitting really nice for a super strong hold. The doors will be permanently mounted to the frame with long stainless wood screws right into the plywood core of the floor of the boat after the frames are installed. For now I used nuts and bolts just for mock up.





       Finally.... a piece I could mount tomorrow if I had to.... There will be some slight tweaks before that happens    :eye:  :cyclops:








it seals up really tight





I will build up gel coat in the corners of the frame to match the round of the latch hump. I may even build up with peanut butter around the bolts so the nuts fasten down on a flat surface. I will use 5200 on all the protruding hardware upon final installation




The latch and catch alignment is just a little off... this is probably something I will correct with a Dremel and gel coat.




Aside for the few modifications mentioned above, that's pretty much it for these hatches until they are installed. The gel coat has been lightly sanded just to shape and clean up any casting marks and will be sprayed with a final finish after installation.  The doors will be sprayed again with gel coat and an anti skid grit. The frame face will be ground to a taper and married into the fiberglass of the floor for a seamless finish with the floor. All you will see is the door.

The other door is sitting in the mold waiting for its final layers of glass and gel coat. I will post if anything interesting happens along the way but this is pretty much the end of this thread.

In closing you either have to be very good at glass work or very patient to make these hatches, but anyone can make them. They took me more hours than I want to count and I have no intentions on making anymore. However as my first attempt ever at mold making I am beyond pleased with how they came out and how functional they are which made them worth the effort. If I could do it anyone can! Good luck and post your builds!!!!!

Did someone say bait station transom cap?????? :compress:  :compress:  :compress:

[CLM65]

Nice job, Steve   You should be proud

[Capt. Bob]

Great stuff Koz.