Limber holes when filled below deck with foam?

[tdrudd87]

Hi guys,

Just planning ahead for when I finish glassing stringers and want to put the floor down.

If the between stringer passages are filled with foam, is there any need for limber or drain holes? The bilge on my boat is also the motor well for the I/O volvo. the original design had no foam, limber holes in each stringer, and then a drain from the underdeck area into the true bilge. There is no other way for water to get in this area except if I put the holes back in, otherwise it is completly glassed closed. I'm thinking it would be a pain to have a livewell typ plug in this drain so that the underdeck area didn't get water in it from regular operation, and then have to remove it for ventilation.

It is a trailered boat, so it will not sit in water for more than a weekend.

My concern is that the below deck are will need to breathe, even if it is foam filled?

Thanks for the guidance!
Terry

 

[tdrudd87]

Re: Limber holes when filled below deck with foam?

Here are some pics to better show what I am talking about.

The current motor well design:

And how the stringers are cut to make this shape:

THis pic shows the one drain hole from the under-deck area to the motorwell bilge:

There were also limber holes in each stringer. I am concerned that by putting these holes back it it will actually allow more water in the under-deck area, such as normal deck runoff from swimming and the like, and may be better with no limber and drain holes, and filling with foam instead.

Any thoughts guys?

Thanks!
Terry

 

[Bob_VT]

Re: Limber holes when filled below deck with foam?

Water will get in there...... just a fact

Put limber holes in so if any gets in ....it will route to the bilge.

Many people use the edge of a plastic spoon to insure smooth rounded edges on the high side of the stringer leading to the holes.

 

[tdrudd87]

Re: Limber holes when filled below deck with foam?

Thanks Bob, If figured that was the right answer.

Can anyone tell me, on a fiberglass hull, with poured in foam, how do the stringer areas drain?

Thanks!
Terry

 

[MTribe08]

Re: Limber holes when filled below deck with foam?

They normally Dont drain, that why rot occurs. The water sits at the base of the stringer and rots from the bottom up. Put in limber holes with space for water to run/drain and you likely prevent that.

The challenge is creating a space at the base of the stringer while pouring in foam. I've heard of people laying a thick piece of roap in there for the foam to form around, then pulling it out.

 

[tdrudd87]

Re: Limber holes when filled below deck with foam?

I'm still a month away from facing this problem but this thought has been stuck in my head while I was fiahing this evening...

With solid layups and the bilges glassed closed well, and foam filled, I should have a hull life of 20yrs given good maintenance. If I gash the hull on a rock, I will be tearing in for a repar and the deck will be coming up. In the mean time, my boat still floated home, and can be repaired.

With a open bilge and drain holes, the stringers are wet more often but dry out easier. theoretically longer life than foamed in. If I gash the hull on a rock, the boat goes to the bottom and is lost.

My concern is the permeability of the hull introducing moisture to a sealed belowdeck. There will be no openings from the top of the deck, no ski lockers or fuel tanks. solid glass covering the ply tabbed into the hull.

Thoughts from guys in the industry? oops or ondarvr maybe?

Thanks!!!!!!!
Terry