Can someone give me advice on drilling the hull for a thru hull fitting please. Obiously this makes me a little nervous and i'm wondering if there is another option. Use is for a wash down pump that is currently plumbed into the 20 gal fresh water tank. Is it possible to mount an intake under the swim grid to avoid drilling the hull? What is the norm? thats for the help. :roll:
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Thru hull fittings
- Thread starter dutch123
- Start date
Rob & Karen
New member
I have a washdown pump in the cockpit, and I too was reluctant to drill a hole in the hull. I ran the intake hose through the rubber boot into the splash well where it stays when not in use. When I want to use the pump, I hang the hose over the transom into the water next to the motor. Hope this helps.
Rob
Rob
Jack in Alaska
New member
Dutch123,
Drilling a hole in the bottom of ones boat just goes against all common sense but.............if you route the tubing from the fitting up higher than the waterline it will not allow uncontrolled water flow into your boat.
My water intake for the wash down and the live well, factory installed, is in the bottom and tubing routed as explained.
Good luck and thanks for the "hello" when we passed through last month.
Jack
Drilling a hole in the bottom of ones boat just goes against all common sense but.............if you route the tubing from the fitting up higher than the waterline it will not allow uncontrolled water flow into your boat.
My water intake for the wash down and the live well, factory installed, is in the bottom and tubing routed as explained.
Good luck and thanks for the "hello" when we passed through last month.
Jack
matt_unique
New member
As a Tomcat owner with a raw water wash down I envy the fact that you guys have one plumbed to your fresh tank. It would sure make things easier for me where I presently keep Napoleon on a mooring. You could connect to your rinse port on your engine (if equipped) for a fresh water rinse no matter where you are.
Good luck with your project. If you drill through any coring you of course want to make sure you overdrill/undercut/etc.
Good luck with your project. If you drill through any coring you of course want to make sure you overdrill/undercut/etc.
The proper way is to use a hole saw, a fraction of an inch larger than the diameter of the bronze threaded thru hull fitting. You under cut the core back by about 1/4". Use a coat hanger, allen wrench, or Dremel tool. Fill this under cut with epoxy so that it gives both support and keeps water from the core. Put sealant (4200 would be good) under the outer part of the fitting (strainer)--and then make a "backing block" under the inner nut. Use the nut to tighten down on the sealant.
You can run a tube over board. I used a diaphragm pump and put the intake tube over board. This was my choice on a 22.
You can run a tube over board. I used a diaphragm pump and put the intake tube over board. This was my choice on a 22.
Ted Osborne
New member
Dutch123. I don't like the idea of a thru hull if you don't have to do it. We have the pump under the gunnel and just toss the intake overboard.
Our boat came with a thru hull for a livewell pump and I can't wait to get rid of the bloody thing. I just don't like holes below the waterline with a hull that is cored. I'll be taking care of it sometime this year. I like the "throw the intake over the side when you want to use it" school of thought.
Rick
Rick
Fairbanks Fisher
New member
I've got a factory installed raw water washdown system. I went out and took a couple of pictures of the thru hull fitting from inside and out and posted them in my photo album in case you might be interested.
Good luck.
Good luck.
We had thru-hulls on our sailboats for the engine coolant, depthsounder, and speedos. Sailboat hulls rarely allow transom mounted things like this. A big Allen wrench on a drill will carve out the hull core and this resultant space needs to be filled with a good epoxy intended for this purpose.
20+ years with the San Juan 28 and these fittings and not a single issue with the thru hulls. Hole preparation is vital, this ain't a one-day project.
-- Chuck
20+ years with the San Juan 28 and these fittings and not a single issue with the thru hulls. Hole preparation is vital, this ain't a one-day project.
-- Chuck
matt_unique
New member
Fairbanks Fisher":26gqd9ey said:I've got a factory installed raw water washdown system. I went out and took a couple of pictures of the thru hull fitting from inside and out and posted them in my photo album in case you might be interested.
Good luck.
You know, looking at those pictures I wonder if those things are mounted through solid glass?
The indentation looks just like the spot on Tomcat with solid glass (for In-Hull transducers).
Captains Cat
New member
Matt, I thought about that too when I saw the pix. Could be though that it's just an indentation for the bilge water to collect and is still cored. Hopefully, the first time someone drills through it, they'll let us all know! :thup
Charlie
Charlie
From the various fiberglass projects I have done on my boat and the experience Thataway documented on his fiberglass repairs, I would not assume the factory followed proper procedures for installing any hatch or thru-hull. It takes a lot of time to properly bed a thru-hull as explained in many forums here and factory does not want to and I am inclined to say, from my experience, the factory does not follow the procedures to protect cored hulls.
With that said, I like water intakes through thru-hulls. When properly located, you can use the system while underway. The location of the bait pump intake the factory installed on my boat was too high. It only works when the boat is fully stopped. Once we got underway, the thru-hull was out of the water and the bait pump starved for water. It didn't take long for the bait to die. This is one of several examples where I scratched my head wondering why a boat manufacturer missed this.
As Chuck S said, thru-hulls are not an issue, when properly installed. There are multi-million dollar boats with multiple thru-hulls. Once you install one properly, you will never again hesitate to do so.
George
With that said, I like water intakes through thru-hulls. When properly located, you can use the system while underway. The location of the bait pump intake the factory installed on my boat was too high. It only works when the boat is fully stopped. Once we got underway, the thru-hull was out of the water and the bait pump starved for water. It didn't take long for the bait to die. This is one of several examples where I scratched my head wondering why a boat manufacturer missed this.
As Chuck S said, thru-hulls are not an issue, when properly installed. There are multi-million dollar boats with multiple thru-hulls. Once you install one properly, you will never again hesitate to do so.
George
matt_unique
New member
Bad Boy":1v1zo8p5 said:... the factory does not follow the procedures to protect cored hulls...
Considering the entire cost of the boat, one would think they (and other manufacturers) would opt to do this and charge whatever they need to cover the cost. I'm not aware of any manufacturers that seal cored material properly. In fact, most boat yard installers don't do it right.
It would be interesting to learn if the indentation is solid glass as it is on the Tomcat's aft starboard sponson.
Fairbanks Fisher
New member
Using a solid tool handle and tapping on the adjacent hull area and the indented area did not give any indication of density change therefore I would assume a normal cored hull in that area as well.
As an aside, I took a close look at the transom drain thru hull and it appears to have exposed core (see photo added to album). I will be taking out the transom drain fitting, undercutting and sealing the core with epoxy before reinstalling the fitting and I will more than likely remove the raw water thru hull fitting and, if it is not sealed, will undercut and epoxy that as well. Any other thru hull will be gone over the same way (chain locker drain hole). Better safe than sorry. I really like the boat and want to keep it in as good shape as possible.
By the way, I think the reason the chain locker drain is above the bottom of the locker is because the outer clam shell fitting can't go any lower without hull contour interference. Mine is also about an inch from the bottom of the locker.
As an aside, I took a close look at the transom drain thru hull and it appears to have exposed core (see photo added to album). I will be taking out the transom drain fitting, undercutting and sealing the core with epoxy before reinstalling the fitting and I will more than likely remove the raw water thru hull fitting and, if it is not sealed, will undercut and epoxy that as well. Any other thru hull will be gone over the same way (chain locker drain hole). Better safe than sorry. I really like the boat and want to keep it in as good shape as possible.
By the way, I think the reason the chain locker drain is above the bottom of the locker is because the outer clam shell fitting can't go any lower without hull contour interference. Mine is also about an inch from the bottom of the locker.
C-Squirt,
I believe the reason the side drain hole is not at the bottom is because that's as low as they could go with their drill. If it were my boat, I would drill down through your hull with an oversized bit, fill with epoxy and re-drill to the size drain hole you want. This way, you will not have any standing water in the rode locker.
Your discovery of the lack of protection of the coring with your transom drain plug pretty much says it all for C-Dory's standard operating procedure. You are wise to epoxy the area. Doesn't it seem likely they did the same thing for your water pick-up thru-hull? Maybe you should check that, too?
George
I believe the reason the side drain hole is not at the bottom is because that's as low as they could go with their drill. If it were my boat, I would drill down through your hull with an oversized bit, fill with epoxy and re-drill to the size drain hole you want. This way, you will not have any standing water in the rode locker.
Your discovery of the lack of protection of the coring with your transom drain plug pretty much says it all for C-Dory's standard operating procedure. You are wise to epoxy the area. Doesn't it seem likely they did the same thing for your water pick-up thru-hull? Maybe you should check that, too?
George
The sides of the C Dory are solid glass. If one needs to remove the drain plug or work on the boat, it is best to go ahead and repair it as above. We also found a void between the transom and the core on the bottom, aft of the c Dory 25 when we were rebuilding it. That was filled with solid glass.
Fairbanks Fisher
New member
George,
I didn't think of the drill being the limiting factor for the position of the rode locker drain hole. With all of the fancy drills out there you would think that wouldn't be an issue. I've done a fair amount of work on small aircraft and confined spaces always demanded specialty tools - including drills for minimal clearances.
I am definitely going to remove the washdown water pick-up fitting and seal it if it isn't. I've got time before C-Squirt makes her maiden voyage and I'll use it to bring small dings like this up to snuff. Fortunately, Bob has enabled me to learn something about how to do these fixes the right way.
Knowing that C-Dory is now owned and run by Liquid Marine and not the same folks as when my boat was built, I think we should give them a fair chance to show us what they can do. They seem to be doing the right things in other aspects of running the company. Hopefully that will carry over to detail quality control as well.
I didn't think of the drill being the limiting factor for the position of the rode locker drain hole. With all of the fancy drills out there you would think that wouldn't be an issue. I've done a fair amount of work on small aircraft and confined spaces always demanded specialty tools - including drills for minimal clearances.
I am definitely going to remove the washdown water pick-up fitting and seal it if it isn't. I've got time before C-Squirt makes her maiden voyage and I'll use it to bring small dings like this up to snuff. Fortunately, Bob has enabled me to learn something about how to do these fixes the right way.
Knowing that C-Dory is now owned and run by Liquid Marine and not the same folks as when my boat was built, I think we should give them a fair chance to show us what they can do. They seem to be doing the right things in other aspects of running the company. Hopefully that will carry over to detail quality control as well.