Which thru hull connection?

[Time Off]

I'm installing a Shurflo Washdown System in my TJ but still need to do the dirty deed of boring a hole in my boat. I'm trying to decide on which thru hull connection to use. I know the bronze is supposed to be fairly mineral resistant but the new plastics are pretty good too. I also found one with a built in strainer that might be better for keeping debris out. Any suggestions?

[Pitch Pocket]

not plastic

[NETONE]

What you mean not plastic...Why on earth would you want to have a dissimular metal, bronze, in contact with your alum haul, the plastic will not cause and issues with electrosis or other saltwater related issues. The plastic is low cost and can be installed so its water tight with simple marine grade calking, and replace, and years later when replacing you will not have issues with dissimular metal wear....

Bronze + aluminum + saltwater = Bad Stuff
The nylon ones tend to break.
Take your choice.

I would use the nylon one and inspect it regularly.

[Time Off]

I also found stainless steel. Would that cause electrolosis with Aluminum?

[Silver Hilton]

Nylon would be my choice. Be careful not to over torque it on the install and you'll be fine.

I don't have a debris strainer on mine, and it works fine. North River installed it using a nylon fitting.

Yes, stainless steel is also a BIG problem with aluminum.

[Dinikin]

Why not drill a hole and weld an alluminum pipe, already bent. Also put a turn valve just in case.

[Slugranch]

Plastic, and a sea **** . Electrolosis is a misnomer,it's really galvanic corrosion that eats up aluminum, and of course zinc.

[Time Off]

Yes, I was planning on using a seacock or ball valve. I think I will go with nylon, thanks for all the responses.

[Reelentless]

I just installed a washdown pump on my Sea Sport. Sea Sport recommended a new product called Marelon. It looks like plastic, but its as strong as steel. West Marine has them.

Edit: Pitch Pocket is right. Never use plastic below the waterline.

[ 01-31-2004, 08:54 AM: Message edited by: SeaSportdude ]

Garyk,
Valve is a good idea but if the through hull fitting cracks it won't do any good. I don't know what “Marelon” is but if it were me I would look into it or a high quality nylon one for an aluminum boat and bronze for a fiberglass boat. Stainless has problems when immersed in saltwater.

[Reelentless]

Marelon-

In the late 1970's, a search was undertaken for a material that could replace the traditional bronze and brass plumbing components in boats. The frequency of severe corrosion, and the problem of conductivity in bronze, had long been a source of frustration for designers and boat builders. And, owners had to deal with the risk and costs of this ancient metal in their modern boats.

Marelon® is a formulation of glass reinforced Dupont Zytel®. It is optimized for marine use above and below the waterline with maximum U.V. inhibitors, and it will not support combustion. Additional marine benefits of the material are its extreme range of operating temperature and it's resistance to abrupt changes in temperature.

Thanks for the information, it looks like Marelon is the right material to use.

http://www.powerandmotoryacht.com/ma.../0403hullcare/

http://www.boats.com/content/default...contentid=1904

[ 02-02-2004, 04:08 PM: Message edited by: Keta ]

[Pitch Pocket]

I guess for an aluminum boat the brass may cause a problem, but if it is on the bottom of the boat, I wouldn't want to hit anything with a plastic through hull. I could just imagine snapping one off. But if that is better than the dissimilar metals, by all means go plastic. All the through hulls on my SeaSport are brass, but then it's a glass boat.

[Rakkasan]

Or you could make it simple and rig a drop line for your intake that you put over the side when you use your wash down and coil it back up when you are done. Then you do no have to worry about putting a hole in the bottom of you boat or unpluggin it or having it break off. It is also easy to flush out when you have been in the salt water. Rig it nice and neat and you will never know it is there.

[ 02-02-2004, 05:52 PM: Message edited by: DSRods ]

[garyk]

TimeOff, take a close look at whatever plastic fitting you buy.

I also just purchased washdown system and had the dealer set me up with the fittings. Later on, I notice the plastic thru-hull fitting's package specifically says 'not for below waterline use'.

Why'd this major dealer sell me something not rated for the application .

I'm also going to install a safety shutoff on the inside.