TOPIC: ok question of the day? below deck drain hole

OK I have laid the two sides of the main floor down . I cut into one of my stringers right at the transom, I wanted to see of the scuff marks at the back broke through to the inside of the floor, they didn't. they are under the bottom of the transom. so I will fill and re-shape. My question for the group is i have four drain holes, two for the splashwell, one for the deck drain. and one under the deck in the center of the transom. Since I am sealing the deck under the floor and hopefully will not see any more water do I need the drain hole.???????? Can I fill it in and use the one above deck.??????? I hope to lay the center portion in the next few days. I can glass it up from the inside and then fiberfill it from the outside. a little guidance would help. that would be one more thing to worry about.

billy

You will get different ideas on that I'd think. I'd keep the drain holes but the one from bilge should have a good FM insert epoxyed in so it wont come loose from inserting and removing plug. There could one day be a crack you can't notice and water will find its way in I fear. The motor well in a g3 only has one drain hole and is kinda slow to drain so I'd suggest keeping it the way it is. Now I'll wait for the Cons

You may want to review this thread about sealing below deck on my Sabre Craft restoration project.

www.fiberglassics.com/fiberglassics-forums/home/main-forum/advice-needed-on-venting-sealed-bilge

I sealed mine and it generated a lot of interesting discussion and useful information on the topic.

Hope that helps,
Bill

ok i had the perfect vent up front under that compartment i cut a hole in and put a hatch, the stringers went under the wall there and there were small voids where the stringers stopped and the wall began. i laid glass there to get a water tite space. hahaha , i can go back and rip the glass off give me a few vents but there are four stringers and two of them wont be vented. i must have missed that class. ok i can go and cut a inspection port up front but again not all will get vented. i can cut some two inch holes in the stringers in the back through to the outside stringers
and then vent in the back , haven't put the center of the floor down yet. its going to kill me to drill a hole in that floor. ok i can go ahead and drill through the stringers run a few pieces of pvc pipe put a Tee in it and run it under the splashwell over the sides and put two small vents at the back.

ok im screwed up now. i cannot find a vent for the deck that is waterproof, the fuel tank vents but they are too small. the flange vents are open to the weather. 3" is too much for my tube. they make a mushroom vent but you have to close it off to be waterproof. i need something that i can mount at the back and pull air in and turn the other way to pull it out. i might be able to put a water trap in the line to drain water to the floor before it gets under the floor . why why why . i was happy sealing the floor up. hahaha help. i need a thru hull vent facing the front that is waterproof or a mushroom vent at will repel water.

help.

Seems to me like you are going a bit too far on the venting thing. I was only concerned with pressure relief for the "sealed" compartment. Knowing that there was no way I filled the compartments so well that they were not connected to each other somewhere, I simply drilled a 1/4" hole in the floor under a seat and ran a nylon tube up several inches. And one more up under the bow on the raised section. Now, on the other hand, if you are concerned about the fuel vapor issue, I guess you are not over doing it. Your boat may be different, but I could see no way there was going to be a fuel vapor issue on my boat with an outboard, a removable gas tank, and an completely open section under the motor-well.

I think the "ram air-in one side/out the other" approach with AIR vents doesn't compare to a good 3" Y-ducted bilge blower. I'd turn both vents to the stern and hook up the flexible aluminum dryer vent to both.

As for the transom WATER drain vents, I'd keep both. I use these fittings almost exclusively in my restorations...good looking, tight fitting and you can't lose the plug:

i like the drain plug ... what is is the tube thru the transom. i have 1" holes now and i bought the brass tubes. and the flaring tool. i would like to use that for the under deck drain tube. won't worry about it coming out and can vent through it too. the diameter of the tube thru the transom????????
i think i have figured out the venting to the areas sealed. install a tube up front into the storage compartment i made and just use an elbow thru the wall, and that will be concealed under the bunk benches. then buy a small blower for the rear under the splash-well and vent them under the gunnell ,an elbow turned toward the rear. water wont get up in there and the outside of the boat will remain intact.

billy

ok i really would like to pick somebodys brain before i go any further. i have the center of the floor i haven't put down yet. i have three small sections up front i can rip up if i need to and the repair that. i just went to west marine and bought a 7x9 inspection hatch (it says it is water tight ) and a 3 inch blower. i didnt want to use the flex pipe. i will get pvc stuff to vent. i want to try to get a couple of tubes in the front for the sealed areas and then put the blower in the rear under the splashwell and vent it under the gunnell but i want approval before i do this i didnt want to cut a 7 inch hole in the floor and now the blower can be mounted to the transom for future repairs and just pipe it under the floor. same principal just no need for a hatch in the floor. please someone can contact me for a few minutes i would fell a lot more comfortable i Don't think i will get fuel vapors under the floor , really dont but well there. email me at This email address is being protected from spambots. You need JavaScript enabled to view it. and i can contact you.

Personally I think drain plugs are a pain in the butt. I would glass them over and use the bilge pump. With the new invasive species laws requiring the removal of the plug all of the time, I'm going to eliminate the plugs on everything I have. If I stored the boats outside where they might fill with water from a bad tarp or something, I would feel differently.

Todd