Pan screws into deck for battery box for CS?

[boogieblues50]

Hi all
I am going to install my 2 trolling motor battery's up front on My 198 DLV...Was wondering what lenght screws i can use in the deck without going to deep into the hull...Any hints or other ideas for mounting the battery trays would be welcome...Thanks Boogieblues

[hogtown_usa]

You won't hurt anything by putting a long screw in as long as it doesn't hit the outer hull :o . The holding power of the screw is going to be in the thick fiberglass at the deck surface. Under this fiberglass is closed cell foam flotation. A screw long enough to hold what you're mounting and fully penetrate the solid fiberglass deck is all that is needed. Make sure you squirt some 3M 5200 sealant into the screw hole and fully coat the threads and under the screw head before final installation. 012

[Fillet1]

You can use 1/2 in to 3/4 long screws up there. I have the batt boxes with the nylon straps that go over the lids. They let you get the boxes/batteries out easier if necessary.

[sportskiff]

fillit,
Please post a pic or two, please.
Reggie

[Fillet1]

Reggie,

I have them in the stern of my boat. There are some pics here somewhere....

[FLboy3]

Maybe a dumb question, but if you use a screw long enough to go into the closed cell foam, would that creat a leak in the closed cell and it would no longer be closed cell. I would think it could take on water in any holes punched into them. Just a thought. I think of this when I'm moving something in the boat that requires holes drilled for screws and the drill go's through the glass deck and then it reaches what seems like a hollow area. I try not to drill to far into the hollow area due to the closed cell foam stringers.....Darell

[bobreeves]

Closed Cell Foam: I'm no expert, but from my understanding you should be able to drill a 2" diameter hole all the way through a foam 'log' in a skiff and the it should not effect the flotation except to reduce it by the volume that you removed drilling the hole. In other words, it is closed cell all the way through, not just at the surface.

[Fillet1]

Fl Boy-

Closed cell foam is made of millions of closed "bubbles" that will not leak water from one area to another. A sponge, on the other hand is open celled and will transfer water. If you had open cell foam, theoretically a single screw hole could saturate all the foam in the boat over time. Closed cell will not. Only the path of the screw will damage the immediate foam it penetrates. Fill the screw hole with 5200 prior to putting the screw in and there is no problem. Now, water in the hull is different than the foam issue. Thats where water leaks into the hull through unsealed screw holes, migrates passed the foam (because it wont absorb it) and collects between the hull and the foam. You then have to drill the transom to let it out.

[bobreeves]

I still say CS should put O-ring sealed drain hole fittings at the lowest point on the transom of EVERY skiff they make. The things only cost $5. It seems no matter how careful they are assembled, some water eventually gets in there and there should be a factory provided way to get it out. We shouldn't have to be drilling holes in our boats to let out the water. 004

[redfish74]

Why don't you 4200 or 5200 a board down to the deck then put your fasteners in the board.

[FLboy3]

Another question is how do you get the 5200 to stay down in the hole. I know everyones squirted it in the hole and watch it bubble back out again. I have tried useing a needle to create a air hole and tried packing in with drill ends and it still wants to bubble back out. I guess its because of pressure in the hull. Anyone else have this problem.

[bobreeves]

I get the 4200 in tubes at Walmart, then attempt to put some in the hole, which as you point out is not always all that successful. Then I insert the screw into the tube as far as it will go and that coats the threads really well. This combination should seal up well. It worked for me - I redid every single screw that penetrated my inner hull after finding water between the hulls.

[Dave]

As Bob mentioned, put a small dollop of 5200 in or on top of the hole, put some on the screw, near the tip and when it's treaded into the hole, it will seal the area around the threads and give you a watertight seal.

If you are just trying to seal an existing hole, (not wanting to drive a screw in it) try using a toothpick to swirl the 5200 around in the hole. You might have to add some 5200 as you work the stuff in the hole, in order to get it filled without air pockets. It's often elpful (and I don't hesitate) to enlarge the hole somewhat with a larger drill bit. Naphtha (lighter fluid) is a very good clean up solvent for uncured 5200. If the hole is on the transom or other vertical surface, do the toothpick act and just after you put in the last bit of 5200, cover the hole with masking tape to keep gravity from causing the 5200 to drain out the hole. Leave the tape on at least overnight or until the slow curing sealant has had time to firm up. Another tip here is to NOT press the 5200 into the hole when you apply the tape. This should allow the cured 5200 to be just proud of the surface when you remove the tape. You can then trim the 5200 back flush with the surface of the transom, instead of having a depression at the surface.

Dave

[FLboy3]

Dave your last bit of info is where I have the problem. Filling holes where I'v moved something and wanting to patch the hole. After getting the 5200 on and around the hole, it gets all dirty and looks like crap. Do you think marine tex would be as good to patch screw holes in the deck and be water proof. It at least can be sanded off and not be sticky. I have also used a patch fix that comes in a tube about the size of a roll of quarters that you cut off a small piece and roll it around with your fingers to mix the inner paste hardner with the outer puddy. It works pretty good and can be sanded also. That 5200 is a pain in the but to work with other than sealing new screws.....Darell

[Dave]

I'm familiar with Marine Tex and the two part epoxys sticks you roll and knead, to activate. They'll both probably work but because they set up rock hard, might break loose along the edges over time and allow water to penetrate the hole. Most everything expands and contracts, with changes in temperature and humidity, even things that we don't ordinarily think could move. I have the luxury of having an air hose available to clean out small crevices and holes but if the hole were under a deck or out of way place, I personally wouldn't be concerned about a few specks of dirt in the mix. If the area can be cleaned well, is free of oily contaminates, and bone dry, I sometimes opt to use marine grade silicone adhesive to fill a hole, especially where a wire or cable runs through the hole. This product sticks tight to almost any dry & clean surface, stays tight, and remains flexible to move as needed.

I've used the epoxy sticks for other repairs (not my boat) with mixed results - basically I don't like the stuff. Marine Tex is great for gelcoat repairs and is about all I've used over the years for repairing small to medium sized chips and gouges in gelcoat.

Dave

[seacrets]

I've used Marine Tex for patching holes with no problems.

[bobreeves]

Dave - excellent point about the expansion / contraction issue. If the coefficient of expansion of fiberglass with gel-coat is not exactly the same as Marine Tex, then as you point out, there exists the possibility that the patch might leak at some point in the future. I would use 5200 below the waterline and only use Marine Tex above the waterline myself - for holes.

Oops - are we drifting away from the original content 006? We just can't help ourselves. The information sharing on this site is incredible thumbsup.