Using Fiberglass Tubes for Through-hull Drains

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Vance's Revenge
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Using Fiberglass Tubes for Through-hull Drains

Postby Vance's Revenge » Sat Nov 21, 2020 8:49 pm

[Separated from another discussion on a different topic--Moderator]

I replaced my rotted brass tubes by epoxying-in fiberglass tubes. Easy--maybe even easier than brass--to install and never will rot or corrode again.

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Phil T
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Re: Using Fiberglass Tubes for Through-hull Drains

Postby Phil T » Sat Nov 21, 2020 9:10 pm

Vance - Can you share a link to where one can purchase these?
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1992 Outrage 17, 1992 Evinrude 115

Vance's Revenge
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Re: Source for Fiberglass Tubes to Use as Drains

Postby Vance's Revenge » Sun Nov 22, 2020 12:44 am

At the beginning of my restoration I couldn’t find a source for fiberglass tubing so I made my own with West Systems epoxy and these biaxial sleeves. I later then found other tubes with thicker walls sold by Max Gain and used them for some of my drains. The have walls thicker than necessary. I did notice just recently that McMaster Carr also sells them. I have not personally used these.

[A new topic, changes to REVENGE 22 live well plumbing, is now a separate thread--Moderator]

jimh
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Re: Using Fiberglass Tubes for Through-hull Drains

Postby jimh » Sun Nov 22, 2020 11:39 am

When the wall thickness of the tubing increases, the effectiveness of the drain is reduced. The original drains use a rather thin-wall brass tubing, so the effective size of the drain is nearly the same as the hole size.

What is the inside diameter of the fiberglass tubes you are using for drains?

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Re: Using Fiberglass Tubes for Through-hull Drains

Postby Vance's Revenge » Sun Nov 22, 2020 12:30 pm

jimh wrote:When the wall thickness of the tubing increases, the effectiveness of the drain is reduced. The original drains use a rather thin-wall brass tubing, so the effective size of the drain is nearly the same as the hole size.

What is the inside diameter of the fiberglass tubes you are using for drains?


The flow is not reduced if you replace the brass tubes with fiberglass tubes with the same ID. You have to increase the size of the factory holes but that is an incredibly easy and inexpensive process. In fact, I had already purchased the brass tubing, O rings and flare tools before I made the decision to switch to fiberglass. Switching to fiberglass tubes are way less expensive (you don't need to purchase flange tools) and will never rot or corrode.


To increase the size of the holes purchase this $7.99 drum sanding kit from Harbor Freight https://www.harborfreight.com/sanding-d ... 60741.html . Insert the largest drum that will fit in your hole and slowly sand the hole larger. When you get the tube to slide in, on each side you know you have the correct size. Once you have cut the foam out to the new diameter, clean everything well with acetone and the hull is ready.

Then sand the outside of the Fiberglass tube, clean it with acetone and epoxy it in place. I used white Marine Tex because it is so easy to use.

I like Marine Tex because if you catch it at the correct dry time you can use water and a tongue depressor to smooth it out instead of waiting until hard to sand. You can literally use water and your finger to smooth it out to a shiny finish. You get good at it to the point sand paper is not necessary.

If you are restoring your boat and will be sanding for paint or gelcoat, you can leave the tubes slightly long and sand them down to a completely smooth finish.

[A new topic about how to modify the way water drains on a 22-foot hull is now moved to its own thread--Moderator]

Stayinstrewn
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Re: Using Fiberglass Tubes for Through-hull Drains

Postby Stayinstrewn » Wed Nov 25, 2020 12:12 am

[This comment about hull modifications to improve drainage is moved to the new thread on that topic. Please let this topic remain just on the use of fiberglass tubes to replace brass tubes, and not on how to make substantial modifications to Boston Whaler boat hulls with the goal of improving them.--Moderator
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Re: Using Fiberglass Tubes for Through-hull Drains

Postby Vance's Revenge » Wed Nov 25, 2020 10:58 am

[A newly introduced topic about how to modify the 22-foot hull to improve the flow of water draining overboard from the deck is now moved to its own thread. Please let this thread remain only on the topic of using fiberglass tubes to replace brass tubes in overboard hull drains or other drains on a Boston Whaler boat. This thread has twice been pulled off topic to discuss particular applications in which fiberglass tubes have been used, but the use of a fiberglass tube to replace a brass tube is somewhat universal, and not limited to the use made in the very substantial modification to a 22-foot hull that have been introduced in this thread--Moderator]