Standpipe system on fiberglass boat?

[BAD ORCA]

Im just asking out of pure curiosity, not considering converting my boat or anything, but my favorite youtube channel sails an aluminum boat. They use a single standpipe to get all their water because they sail mostly in freezing northern latitudes.

It got me wondering if this sort of a system is possible or is even used on any fiberglass boats that might sail in freezing winter conditions? It seems it would completely eliminate the possibility of freezing seacocks and eliminate the need to winterize them, allowing for more active sailing.

Is a 'seachest' system basically the same thing?

[Matt Johnson]

Originally Posted by BAD ORCA

Im just asking out of pure curiosity, not considering converting my boat or anything, but my favorite youtube channel sails an aluminum boat. They use a single standpipe to get all their water because they sail mostly in freezing northern latitudes.



It got me wondering if this sort of a system is possible or is even used on any fiberglass boats that might sail in freezing winter conditions? It seems it would completely eliminate the possibility of freezing seacocks and eliminate the need to winterize them, allowing for more active sailing.



Is a 'seachest' system basically the same thing?

Yes, a sea chest is the same basic idea. But they often don't extend above the waterline, so less effective.

A standpipe is totally possible in a fiberglass boat. Often the deck drains on older boats were just fiberglass tubes running down from deck to the hull. And the rudder's bottom bearing are setup similar.

[Matt Johnson]

And they need to be tapered to allow the ice to push itself out as it expands when freezing.

[BAD ORCA]

Interesting, thank you.

[s/v Jedi]

The standpipes we have are schedule 80 PVC pipes that are fiberglassed into our hull after flame treatment (for extra adhesion).

There’s fiberglass pipe as well, Centek for example

[SailingHarmonie]

It is usually done on fiberglass boats not to deal with Arctic climates, but to reduce the number of hull fittings.

We have a standpipe/seachest on our boat that feeds the engine, generator, two HAVAC pumps, and the watermaker. Reducing what in "normal" practice would be 6 through hulls to one. If properly designed, they work a treat.

[s/v Jedi]

Terms are used in confusing ways. A standpipe comes up to above waterline and is used for discharge. A through hull fitting, a sea chest and a short pipe with a valve below waterline are used for intake.

[thinwater]

I'm not seeing how this reduces the chance of freezing. The seachest can still freeze and you still have the many small lines coming off the seachest. If it does freeze you are cooked, and the chance of damamge from freezing may be greater.



Sort of a case of puting all your eggs in one basket, and then watching the basket. Post a link.

[Panope]

Originally Posted by s/v Jedi

Terms are used in confusing ways. A standpipe comes up to above waterline and is used for discharge. A through hull fitting, a sea chest and a short pipe with a valve below waterline are used for intake.

This is the engine raw water INTAKE.

Upper end of the Pipe is above waterline.

I have always called this a "standpipe".

Should I be calling it something else?

[Matt Johnson]

Originally Posted by Panope

This is the engine raw water INTAKE.



Upper end of the Pipe is above waterline.



I have always called this a "standpipe".



Should I be calling it something else?

It's a standpipe. We had almost all our intakes so the valve was above the water line too. The only time it's necessary is if the pump needs to be below the waterline - or just add a boost pump.

Edit - awesome job with the organization of your mechanical area!

[s/v Jedi]

Originally Posted by Panope

This is the engine raw water INTAKE.

Upper end of the Pipe is above waterline.

I have always called this a "standpipe".

Should I be calling it something else?

Yes, that is a standpipe (above waterline). I’m not a fan of those strainers BTW and recommend you clean the O-rings every 3 months, only using silicone grease to lube them.

[Benz]

I use fiberglass pipes glassed-in to my fiberglass hull, with the seacocks above the waterline. I've let the boat over-winter in the water and had no issues with freezing, but the pipes are pretty hefty, and the ice can always squeeze up or down.

[s/v Jedi]

This is from memory but I think I have it right: Dashew used 2” diameter schedule 80 PVC. A 2-5/8” diameter exhaust hose is a perfect fit around it and he used this to connect to schedule 40 PVC but I’m not remembering what fitting went inside the hose at that end.

When I clean the standpipe, I take the hose with everything that is higher off and use a threaded rod for cleaning.

I would prefer Centek fiberglass exhaust pipe butthe schedule 80 PVC seems a solid solution as well.

[s/v Jedi]

I actually found some pictures from when I replaced the schedule 40 part. The standpipe is the grey schedule 80 coming up to the exhaust hose coupling. The other picture shows it’s pipe going into the hose from above as well.

The small connection is the vent.

[Panope]

Originally Posted by s/v Jedi

Yes, that is a standpipe (above waterline). I’m not a fan of those strainers BTW and recommend you clean the O-rings every 3 months, only using silicone grease to lube them.

It seems that I have been lucky because I open the strainer only twice per year and have never added grease since the original install, 10 years ago. But, thanks for the reminder, I'm greasing it now.

I too was not a fan. I chose that model because with the lid removed, a rod can be passed through vertically. Because it, the stand pipe, and valve are all in alignment, blockages can be cleared without a drop of water coming aboard.

I guess maybe I am now a fan, considering the lack of trouble.