CONTINUOUSWAVE

Brass or plastic drain tubes?

I have the flaring tool, but came across the TH Marine plastic threaded units and wondered what experiences others have with these. I need to replace all 3 brass drains on my 15' Whaler project and the ideal of plastic is attractive since they will never corrode, but I have concerns on plastic cracking.

D-

Plastic can be very durable depending upon exactly which plastic is chosen. Marelon, I believe, is the name, is a plastic used for through hull fittings and valves. I used it on a previous SeaRay for supply and discharge fittings on a marine toilet. After 18 years the fittings showed no sign of deterioration. Thick wall PVC pipe is a commonly used material for waste piping in homes. I have a PVC water line exposed to sunlight in the back yard. It has shown no sign of deterioration after 15 years of exposure to daily sunlight.

Brass is also excellent though the installation requires a higher level if expertise. I've had a good bit of practice in making up brass piping but will leave the through hulls to someone who has done it at least once. If forced to do it myself I'll use plastic.

Keep in mind that several of the drains have a compound cut. The pre-threaded units may not be long or short enough and sit flush given the shape of the hull.

The brass ones are cut to the hull and then the edges rolled back to get the tight seal.

Thanks for the feedback. Years ago on my 13-footer project Whaler the lower transom drain gave me some difficulty when I flared it due to the angle of the transom, and that's why I explored the plastic drain tubes.

The 15-footer has a much more upright transom, so plastic or brass should be an easier install. I'm going to order the two for the engine splash well in brass and think about the lower drain from the inside hull.

D-

Jefecinco wrote:Plastic can be very durable depending upon exactly which plastic is chosen. Marelon, I believe, is the name, is a plastic used for through hull fittings and valves. I used it on a previous SeaRay for supply and discharge fittings on the pe digest site after 18 years the fittings showed no sign of deterioration. Thick wall PVC pipe is a commonly used material for waste piping in homes. I have a PVC water line exposed to sunlight in the back yard. It has shown no sign of deterioration after 15 years of exposure to daily sunlight.

Brass is also excellent though the installation requires a higher level if expertise. I've had a good bit of practice in making up brass piping but will leave the through hulls to someone who has done it at least once. If forced to do it myself I'll use plastic.

Hi Jefecinco, how do you make sure you don't end up with a bad type of plastic? What to look for?

Quinton,

I wish I knew. If was going to do the job I would do some research starting here on CW. I would just post the question in a new thread. There are other forums where I would post the question.

I'm reasonably certain the through hull and seacock on our 2009 190 Montauk is Marelon. It is an OE assemblage from Boston Whaler. I trust Boston Whaler more than other builders so would not hesitate to use a product they use. The USCG may have an on-line listing of acceptable materials used for through hull fittings.

There are many on-line marine supply vendors. One I respect is Jamestown Distributors another is Hamilton Marine. I would visit their websites and check their offerings. No doubt there are many others.

A Google search is often helpful.

After thinking about this, I went brass on all 3 for one simple reason. Plastic is not the material of choice under pressure and since there are drain plugs that screw into the drains, I did not want any concern over cracking (over time) from an over tightened drain plug and extended UV exposure of the flanged portion of the tube. Probably overthought this matter, but figured that brass lasted this long and a replacement brass tube will probably outlast me.

D-

I recently replaced mine on my 15' using brass and worked out well. Bought from Sue at (use to be) Twin Cities.

Why 3? I replaced 4. One in the bilge, 2 in transom splash well, one in the bow storage.

What's your the approx cost of the x4 tubes for a classic montauk? I am in the UK and can only find Moeller brand drain tubes

Mattwarner wrote:What's your the approx cost of the x4 tubes for a classic montauk? I am in the UK and can only find Moeller brand drain tubes

Tubes are tubes and they are sold by the length. I purchased 3" motorwell drain tubes for $3.70ea and the lower drain tube 14" was $16 with shipping on top of that. You can scour the internet like I did or just purchase on Ebay (usually a little more $$ on eBay).

I did not order the bow locker tube since it looks perfect and the transom ones needed the attention.

D-

Matt, mine is not a Montauk, it is a classic (1982) 15' model. I don't remember exactly what I paid but with the tool I think it was a little over $100

If you're thinking of using PVC, the transom drain tube ID is important also because it needs to fit a standard drain plug.