1988 NEWPORT 17 Wood Board on Bottom of Gunwale

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
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Joined: Mon Feb 12, 2018 12:07 am

1988 NEWPORT 17 Wood Board on Bottom of Gunwale

Postby Newportwhaler17 » Mon Feb 12, 2018 12:12 am

[On a 1988 NEWPORT 17 boat] how does the wooden board on the bottom of the gunwale fasten to the inside of the hull?

I need to replace [the wooden board].

Posts: 80
Joined: Sun Mar 06, 2016 1:18 pm

Re: Newport1988 17’

Postby OldKenT » Mon Feb 12, 2018 9:14 am

Boston Whaler calls the wooden board you refer to a "riser". On both my 1985 Newport and my 1976 Newport, the riser is about 10 feet 8 inches long, 2 and 1/8 inches wide and 3/4 inch thick. The riser is fastened to the hull with screws through the interior gel coat and into a 7/8 inch mahogany board (which is approximately the same length as the riser and which is fabricated into the hull - this is shown on the wood locating diagram).

There are eight (8) #10 x 2 and 1/2 inch stainless steel wood screws spaced approximately 18 inches apart. Each screw hole which is drilled into and through the 2 and 1/8 inch width of the riser is countersunk approximately 1/2 inch. This means that the head of the screw is recessed well into the riser, making it difficult to access the head of the screw with the gunnel in place, but I have done it on both boats, so it can be done.

Removal of the riser requires that you (a) remove the #10 x 1 and 1/2 inch screws holding the gunnel to the riser, and (b) then holding the gunnel away from the riser, remove the #10 x 2 and 1/2 inch screws which are recessed into the riser and hold the riser to the hull.

Step (b) is the difficult part because the gunnel does not have lots of flexibility and you need to lift the gunnel away from the riser so that you can insert a screwdriver into the recess in order to remove the screw and then to reinstall that riser after refinishing it.

In my experience the usual long handled screwdriver does not work well until the screw is backed out of the recess. Instead, you should use an offset screwdriver or a ratcheting screwdriver with a small head. I used both to remove the risers on each of my Newports.

Craftsman sells a 5-piece offset screwdriver/bit wrench set as part number 946157 which works very well to do this. It has a ratcheting head and a magnetic bit holder which fits any 1/4 inch hex bit. You may need to purchase a Phillips hex bit that is slightly longer than the one that comes in the set in order to reach the screw head when it is fully recessed.

I found that placing something about 1" wide between the gunnel and the riser on either side of the screw which is to be removed allowed me to access the screw head and to remove all screws and then to reinsert them when reinstalling the risers. The most difficult screws to remove were closest to the stern or away from the side pocket cutouts where flexibility of the gunnel was limited.

Here are a couple of cautions:

If the risers are mildewed, you will need to construct new risers. It is not easy to find 11 foot long pieces of mahogany or teak. If you construct new risers, you can construct them in two parts and lap them at a midpoint between screw holes so that they fit better.

When you remove each original riser, mark it as to port or starboard so that if you need to construct new risers you can place the original and the new side by side and drill the screw holes in exactly the same location and depth as in the original risers. You need to do that so that your screws will be able to access the predrilled holes into the hull or you will be unable to reattach the risers. A drill press works best for accuracy and consistency.

Be sure to use a sealer and several coats of varnish on the risers before installing.

If a screw breaks off when removing it, be sure to remove the portion still in the hull before trying to reinstall the original or a new riser.
When reinstalling, insert all screws into the holes before you lift the riser into position. The 2 and 1/2 inch screws are so long it is difficult to insert them after the riser is moved into position.

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Joined: Mon Feb 12, 2018 12:07 am

Re: 1988 NEWPORT 17 Wood Board on Bottom of Gunwale

Postby Newportwhaler17 » Mon Feb 12, 2018 8:14 pm

Wow, what a great response, all I need to know about my riser. I only have to replace about 2ft. In the stern, I think I can do that ok with a splice and again thanks for the admirable reply-- Mike