Drilling TAFG for Bilge Pump

[KS Dave]

So, comparing my aft-most bilge compartment with Roger's, his has an extra hole for a 3/4" pipe leading aft (and is WAY cleaner - look at that!).


As part of my upcoming 'Bilge Pump 3.0' project, I thought relocating the auto pump egress to the transom and mounting the pump under the quarter berth might be a better option. I could still use my wiring for a water witch in the forward compartment (where I will have the strum). If I were to add a hole to the TAFG here, is a standard circular hole saw the best choice? Or maybe a forstner bit? Will I have two layers to drill through on the TAFG to duplicate the hole the 1 1/2" pipe takes?

I've read a few threads here that say drilling through the TAFG isn't a big deal. Any other general tips from someone who's drilled like this before?

 

[Kenneth K]

If I were to add a hole to the TAFG here, is a standard circular hole saw the best choice? Or maybe a forstner bit?
Definitely the hole saw--it only cuts around the perimeter (a forstner cuts along the entire face of the cut--that's too much material to cut through).

Will I have two layers to drill through on the TAFG to duplicate the hole the 1 1/2" pipe takes?
Once you cut into the face we can see in the picture, the hose will be "under" the TAFG. You'll have to have floor access to the next TAFG section aft (and, every TAFG section after that, if there are any) to continue running it "below" the TAFG. Or, find a TAFG section where the hose can be pulled "above" the TAFG and run where you can visibly see it. But, yeah, you'll likely have at least one other "exit" hole to cut, if not several more.

Any other general tips from someone who's drilled like this before?
Just try figure out before you cut if it's likely that anything else runs behind that area; other bilge hoses, electrical runs, transducer wires (depth, speed), etc.

 

[KS Dave]

If I were to add a hole to the TAFG here, is a standard circular hole saw the best choice? Or maybe a forstner bit?
Definitely the hole saw--it only cuts around the perimeter (a forstner cuts along the entire face of the cut--that's too much material to cut through).

Thanks, Ken. That makes sense. Forstners are a bit more more expensive, and I already own a 1" hole saw, so bonus!

Will I have two layers to drill through on the TAFG to duplicate the hole the 1 1/2" pipe takes?
Once you cut into the face we can see in the picture, the hose will be "under" the TAFG. You'll have to have floor access to the next TAFG section aft (and, every TAFG section after that, if there are any) to continue running it "below" the TAFG. Or, find a TAFG section where the hose can be pulled "above" the TAFG and run where you can visibly see it. But, yeah, you'll likely have at least one other "exit" hole to cut, if not several more.

This is just in front of the engine compartment. The next TAFG might be there. I'm going to try and thread an inspection camera from the other direction to see how that 1 1/2" hose is routed and try and make the new one do likewise, but having an idea of what to expect might help me see it better.

On a related note, I intend to replace that 1 1/2" hose (that comes from the cockpit gusher) with a similar new one - is it reasonable to think I could tape them together and use the old hose as a "pull line"? Or will I have to remove the old and thread the new through? Anyone tried this?

 

[Christian Williams]

I'd certainly start by connecting old hose to new and pulling. I'd sew them together first, then tape, too.

I've been looking at my old Whale hose with just that in mind. Looking at, not looking forward to, since it bends invisibly under inaccessible furniture, and pulling hoses can be irksome.

 

[Doug177]

This might be a controversial subject. I have no idea. The other posters here have been talking about punching holes in their TAFG back to front. I have done that and it is a wonderful way to lay hoses. I would like to know what is under the floor of the bilge and how thick it is. Is it grid down there too with glass cloth and resin. On my 35-3 it seems to be resin and cement dust to fill the hull up to a certain level and then the hull and then the keel. Hit the floor with a hammer and it is as solid as a sidewalk. I was thinking how nice it would be to route out a 1/2" or 3/4" deep sump about 2 inches in diameter to mount my bilge pump strainer in so as to keep most of the rest of the bilge dry by creating a small sump within a sump. I have drilled holes that deep to mount things and ll I get is dust. So what is the composition of the cross section of the bilge floor top to bottom. I have taken the Rule pump that you see out and will just have a hose and strainer attached to an electric whale pump mounted remotely. The red circle shows the spot I am thinking of for the shallow sump within a sump. Centered between the keel bolts and sides. Yes, the boat is on the hard and would not sink and I would drill small test holes first.

 

[Christian Williams]

For me, the reward isn't worth it.

The problem with trying for a dry bilge is the automatic switches. A float switch or a Water Witch reduce the level but can't eliminate it. For the last drops the Ericson community uses the Beach Baster, a sophisticated device our senior moderator Loren Beach developed in his workshop one Thanksgiving long ago.

I figure what's underneath the floor of the low bilge is the lead keel. There's probably a keel stub, no idea how thick it is. Members who have dropped the keel will know.

 

[Doug177]

The Loren Beach "Beach Baster" sounds like it might be related to a "Turkey Baster" but that would be too easy. Loren?

 

[Loren Beach]

The Loren Beach "Beach Baster" sounds like it might be related to a "Turkey Baster" but that would be too easy. Loren?

Oh My. I do indeed use a cheap grocery store "turkey baster" to remove the last quart of water from the bilge after a rain storm. The quest for a dusty bilge is related to OC behavior, perhaps? Naw......

 

[peaman]

At the recent Newport boat show, I saw an interesting product designed to get pretty much the very last drops out of a bilge. A tiny vacuum pump periodically starts, and if resistance is sensed indicating water uptake, will continue to run to completion. The suction tube is very small, preventing any back flow, and the intake uses something resembling a fine scotch-brite pad (there are a few configurations available for different "lowest point" conditions). Obviously, a primary bilge pump would be in place, but once that shuts off, this product will finish he job. I have no connection with the product. The smallest unit is about $800. https://www.aridbilgesystems.com

 

[Christian Williams]

That's four sessions with a psychotherapist.

I'm going to compare warranties between both approaches toward peace of mind.

 

[Alan Gomes]

At the recent Newport boat show, I saw an interesting product designed to get pretty much the very last drops out of a bilge. A tiny vacuum pump periodically starts, and if resistance is sensed indicating water uptake, will continue to run to completion. The suction tube is very small, preventing any back flow, and the intake uses something resembling a fine scotch-brite pad (there are a few configurations available for different "lowest point" conditions). Obviously, a primary bilge pump would be in place, but once that shuts off, this product will finish he job. I have no connection with the product. The smallest unit is about $800. https://www.aridbilgesystems.com

The pictures on their website are interesting. The "before" pictures appear to show a vessel with a severe holding tank leak.

 

[Marlin Prowell]

In the Pacific Northwest, we get a lot of rain in the winter. And in the fall. And in the spring. A lot of water comes down the inside of the mast. A previous owner put a juice jug and a plastic flap at the base of the mast to capture the rain runoff. But the jug fills up quick enough and then spills into the bilge if you don't get to the boat almost every day. I still had to vacuum out the bilge with a turkey baster.

When some heavy rains were predicted, I decided to get more obsessive aggressive. I put another bilge pump inside the juice jug. The outlet hose runs to the galley sink. Now the juice jug never overflows. After 6-8 inches of rain in two days, and two days straight of gale force winds, the bilge is still dry and dusty.

 

[Christian Williams]

Now to get the juice jug dry.

 

[Doug177]

I like the bilge pump, juice jug ploy! Since I am in an area where it does deep freeze in the Winter (it was +20 degrees F this morning). I do worry about mast rain water ooooozing and soaking around keelbolts and then freezing. You know, the expansion thing. I tighten my nuts every Spring, but you don't know what you don't know. Y'all in the balmy Pacific Northwest and baking Southern Cal areas don't have to worry so much.

 

[Doug177]

Here is a little gem that only costs 1/4 of a psychotherapy session.

 

[Kenneth K]

The bilge pockets themselves can be dried with towels, but I never had much luck with a turkey baster for getting under the TAFG. Now, if my mast/shower bilge overflows to the TAFG, I stuff washcloth-sized rags (or longer) into the limber holes between the adjacent bilge sections. Let them sit a few minutes to soak up the water, then remove, wring, and repeat. Usually, by the third time, the rags aren't picking up any more water and the under-TAFG can air dry after that.