Adding Tomcat Thru-Hull for Washdown

John S

Hi guys,
My current marine head and wash-down intake thru-hull was mounted near the bow on my 24 Tomcat.
When underway the intake is out off the water.
I wash my boat and clean fish while underway. I need a working wash down pump. Years ago I was at the Seattle Boat Show and saw a brand new Tomcat with a rear mounted intake strainer on the inside of the port pontoon.
I’m going to drill a hole and put mine there too. I have some concerns about disrupting the water flow so close to my prop.

Does anyone else have a Tomcat with a rearward strainer thru-hull that could show me a picture???

Any other thoughts on any problems with this position?
I’m adding a “high speed” strainer with the grills pointed forward.
Thanks, John

rogerbum

John S · Posted: Sun Apr 26, 2020 4:21 pm Post subject:

Thanks Roger!
I have the 24 tomcat, with your 25 I think you have a mounting bracket on the back for your motors that puts them further away than mine from the hull.
Im assuming your intake is mounted on the tunnel side of the hull?

Thanks

gulfcoast john · Posted: Mon Apr 27, 2020 9:48 pm Post subject:

John,
Yes, you want this through-hull to be on the tunnel side of the port sponson, (or opposite your CHIRP or depth sounder) and lower than your ‘inner cage’ trailer frame guide-on.

It can’t be on the bottom of the sponson because that would drag on the trailer supports.

Your boat and the TC255 differ only in the addition of an engine bracket, which doesn’t matter here. Both boats are ass heavy squatters, the TC255 more so.

I would suggest drilling from the outside sponson in, to be sure you miss the trailer cage etc, after making sure there is nothing in the way inside the sponson. Get a real Groco marine valve with a 500 lb sideways rating and glass it in per the experts (not me!).

If this pic doesn’t work, it’s on the last page of our album.

[/img]http://www.c-brats.com/albums/CAT-O-MINE/DSC03957.sized.jpg[img]

Good Luck!
John[/img]

thataway · Posted: Mon Apr 27, 2020 10:00 pm Post subject:

John,
here you go--just got the IMG mixed up:

John S · Posted: Tue Apr 28, 2020 4:48 am Post subject:

Thanks guys!

Unfortunately I got the response and photo about 10 minutes after I crawled out of my hull from drilling the hole. Smile

I installed a high speed bronze intake strainer. I put it it a little lower on the hull than the one in the picture. It is well below the center trailer guide.
I had already ordered and bought a bronze shut off valve manufactured from "Marine Hardware" that includes a bonding screw.

My intake strainer has the hole for the pipe and four screws around the perimeter. I will try to add a photo soon.

I made a pilot hole from the inside and then drilled with my hole saw from the outside.
Thanks

thataway · Posted: Tue Apr 28, 2020 10:07 am Post subject:

Don't know if you are finished. It is common to add a backing wood block or something like a fiberglass block on the inside just to spread the load out a little. I believe that the 255 is not cored at the point where you drilled the hole.

Good location, and should work well.

John S · Posted: Tue Apr 28, 2020 6:00 pm Post subject:

ricka · Posted: Tue Apr 28, 2020 7:26 pm Post subject: through hull

John
Sounds like you already placed your hole. I drilled mine on the bottom of the port hull toward the tunnel where the hull veers up at a slight angle as per Northwest Marines advice on a 2020 Tomcat. Can not tell you how well it works yet as I believe I have installed one of the check valves in wrong. Just took it out for the 1st time this last weekend and could not get it to prime.
I will let you know how it goes.
Did you install two check valves on yours?
I purchased the graco wash down kit which comes pre mounted on starboard with two check valves and a bronze thru hull.

John S · Posted: Wed May 06, 2020 5:08 am Post subject: Re: through hull

thataway · Posted: Wed May 06, 2020 11:50 am Post subject:

Check valves are notorious for failure. The reason for a check valve would be if there is difficulty priming the pump. Graco is an excellent brand; it is rated to be self priming at up to 36" (C80) and 24" (C60). It does have rigid vanes, vs the flexible vanes as in some wash down system. (The flexible will self prime at a higher elevation from the source.)

Gene Morris · Posted: Wed May 06, 2020 11:54 am Post subject:

We have a factory installed washdown. There was Brass & Stainless mixed with no evident problems. The only problem was the pick up, It was not a high speed pick-up and was not satisfactory. I have since installed a high speed pick-up and works well even at speed. We clean fish on board and also fish albacore, which make a great mess on the boat.

ricka · Posted: Wed May 06, 2020 12:05 pm Post subject: TomCat washdown pump

I had everting installed in the correct direction, it took sticking a cut off hose in the bronze intake mushroom to get it primed. We took it down to Shasta again and had it working for a few minutes.
The issue I have now is the Blue Sea switch panel the factory installed on the transom which was prewired for a wash down pump is only rated for a max 20 amp fuse and the pump calls for a 30 amp. I have looked on the Blue Sea site to find a matching style waterproof switch panel that is rated to take a 30amp fuse. I cant find any brand that is rated for that.
Any Ideas?

John S · Posted: Wed May 06, 2020 2:13 pm Post subject:

ricka · Posted: Wed May 06, 2020 2:54 pm Post subject: Thru Hull

Hi John,
If interested Groco has backing blocks which are made out of a kind of porous fiber so they soak up epoxy real well and they have the nut inserts to fit many bronze flanges. I just posted the pics of my install in my album.

Rick