Install bilge pump here and discharge here, would you?

Hey folks,

As the title suggest, before I make a semi-permanent bilge pump installation, are these thinking's on track? Why or why not?

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Thank you,
Roy Niswanger

You're definitely on the right track. That is pretty much how I installed my bilge pump. The bilge location just forward of the aft hatch is correct. The use of a low energy glue is correct, however, be forewarned that even low energy adhesives will have problems sticking to the polyethylene surface. I have to reglue mine about once a year. You'll need to rough up the surface as much as possible and check the adhesion regularly. The use of the wooden mount is clever and should help.

I used a Rule LoPro bilge pump because of its low profile, but the one you selected should work too.



Here is where I mounted the bilge outlet. It works well. After 7 seasons, I've never had an issue with it. The use of a check valve is critical as you mentioned.



Be aware that the use of a bilge pump is for significant water ingress only such as from rough seas, a storm, or a hull or hatch leak. It doesn't help much for day-to-day fair weather use where just a little water enters. I still use a manual bilge pump or the rear drain plug for that.

There's no need to avoid the use of an automatic pump, the float switch works well and is reliable. And the pump can always still be activated manually. I use a DPST switch, one position is for automatic operation and the other is for manual operation. This way you have both options, which is better than either alone.

I assume you have a decent size sealed lead-acid or better yet a 12V lithium battery onboard which will provide enough run-time operation in the event of an emergency. It needs to be able to run the pump long enough to reach the shore. Be sure to recharge it before each outing.

That's all I can think of, please let me know if you have any other questions.

Thank you pro10is.

My main vetting here is location, conventional wisdom puts it as far aft as possible, but in a yak I think just fwd of the rear hatch is good and you too have confirmed this. I've seen some guys put them just aft of the center hatch of the AI's (humm?). The glue I've been using on HDPE that seems to work VERY good is Loctite 3035 Polyoflen. It's not cheap at about $50 a tube. The idea behind the teak bracket is the upper piece will be the secure point for the bilge strainer which clips to the pump. That upper piece will float atop the main glued piece and fastened by SS hardware (1/4-20 SS threaded insert with 1/4-20 thumb screw), so I can remove the upper piece to remove the entire unit. Also, teak is a decent choice for a wet environment.

That's where I'll put the discharge unless I opt to plumbing like this chap: https://youtu.be/IiceI0a0PTs?t=410 the caveat to this is a discharge constriction from 1/2" ID of a 3/4" bilge pump discharge to a short section of 3/8" ID for this fitting conversion. This coupled with a check valve will put more back-pressure on the centrifugal bilge pump which will increase amperage a degree. I like the concept, but I don't like how he used a SCH40 check valve and modified the internal spring (just too bulky/heavy IMHO). I've already acquired all lighter fittings and will be starting a proof of concept with my multimeter in series to measure amperage of normal 3/4 discharge vs. this setup.

I'm only running an 8Ah LiFePO4 pack...these are much better than wet cell chemistry because of the DOD (depth of discharge), effectively a 7Ah SLA can only supply 12vdc for about 5Ah whereas a LiFePO4 can for near it's full capacity.

Yes, it's really only for emergency, and with my son at the helm of this one, I'd feel a lot more comfortable in case we get into some nasty weather.

_________________
Thank you,
Roy Niswanger

The exact location of the pump is not that critical. As long as the pump can remove most of any excess water, you're fine. If you want to find the lowest point on the boat, observe where any water settles when the boat is level, or better yet, when it's on the water fully loaded.

Concerning the discharge, always keep in mind that the primary job of a bilge pump is to remove water from the hull as quickly as possible in a catastrophic event. This gives the boat a chance to reach shore before sinking or becoming too overladen to move. So, you don't want to do anything that might reduce the GPM output of the pump even a little. You want to keep the discharge as short and direct as possible with as little head as practical and no restrictions of any kind, and you should never do anything to burden the motor. These are very small motors, anything you do to restrict them might have a significant impact on their ability to remove bilge water as quickly as possible in the event of an emergency.

The 8Ah LiFePO4 battery you are using is fine and far better than a sealed lead-acid.

Thanks guys for the tips/advice. Here's how I ended up doing it:

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Thank you,
Roy Niswanger

Excellent work, well thought out and well-engineered.

The only thing I would do differently is to use an automatic bilge float switch along with a manual switch. This would have given you both options whereas now you only have manual operation.

In all the years I've sailed my 2015 TI, I was rarely aware that I actually had water in the hull when using it. Water primarily entered on days with rough seas where I believe the water would enter from the front hatch as that's a known problem on TIs for water ingress. I would get back to shore and empty 10-20 gallons of water out of the drain. This would astonish me and is why I installed a bilge pump in the first place.

On such rough days, I was very busy sailing and not paying attention to water ingress which you can't even check unless you take time to open a hatch and stick your head in to have a look. This is not something you really want to take time to do on rough windy days with heavy waves when your attention is elsewhere. After installing the bilge pump, I would be sailing along in such conditions and suddenly hear the motor activate and then see water streaming out of the discharge. I was very glad the float switch was constantly looking after the situation for me while I was occupied sailing as I didn't think to operate it manually. This is why I would never be without an automatic float switch. Without one, by the time you're aware that there is a problem and then manually activate the pump, it may be too late. Far better to automatically evacuate any water well before it becomes a noticeable problem. With the bilge pump set to auto, I never again had to drain more than a few cups of water out of the drain back at shore.

I can still always manually turn on the pump whenever I want with the switch override, so even if the float switch failed, I would still have the same operation as your setup. However, in six years of use, the float switch has never failed once and I check it regularly.

Thanks for the props. Yes I would have preferred the automatic option as well but saw a lot of internal float switch complaints. I know I could have spent 4-fold or more on a better unit, but this $15 Academy pump is actually highly available not only in their brand but the exact same pump is available as re-branded versions as well. I'm just glad this is done now and I can rest easy when my 16yo son is 5 miles offshore with me. Speaking of, we need to hit Lake Travis for some shake downs and practice for him trolling under sail.

-Roy

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Thank you,
Roy Niswanger

You can add on an external float switch for only $13. They're very reliable.

If you're not interested, then you'll need to let your son know how to check for water ingress. A manually-operated bilge pump won't do a thing by itself to protect him.

Good point, ordered, thank you.

_________________
Thank you,
Roy Niswanger