New Member! Question on Floor Replacement for 1972 17'

[tbergmann93]

Hi all!

In the process of purchasing a 1972 17' Aquasport for a rebuild. The boat I am bringing home this Friday had a previous owner who did a pretty rough job of trying to replace the floor/deck with fiberglassed plywood. I plan on cutting out his handywork and replacing the floor myself (and stringers if needed...though hoping not to).

What is the general process for putting in a new deck from a structural standpoint? Where exactly does the new deck/floor rest on top of and what supports it? I think I may have heard others say that they cut out the old deck and leave a few inches so that they can place the new deck on top of this at the edges, did I mishear that?

How does one go about attaching the new floor (and where to? The stringers?), with epoxy adhesive or mechanical fasteners?

What would your all recommendations be for those who have done this? Thanks!

Tim

[RickK]

The first time I replaced the floor in my 170 I used a skill saw and ran it around the perimeter of the floor, which left about 2" to rest the new floor on. I replaced the old floor with resin coated 5/8" plywood. You can use deck screws and glue to attach the new to old and then cover the entire floor with a couple layers of 3/4oz chopped strand mat (CSM). Here is a link to US Composites and what CSM looks like. http://www.uscomposites.com/mat.html
There will be a gap between the bottom of the floor and the stringers that you can fill in with something like cutoffs from the new plywood. I used pickets from new fencing. They were 1/2 or 5/8". I coated them with resin and screwed them to the top of the stringers. That new floor lasted a good 15 years and then I rebuilt the entire boat.

[tbergmann93]

Perfect, that makes total sense, thanks for the help!

One other question relating to deck height; is the boat as-is self-bailing? I thought I read somewhere about someone raising the deck to make it self bailing, but others mentioned it is naturally self-bailing as is. What's the story? It would be great if I could have it be self bailing...

[dbiscayne]

A 4 stroke, 4 cylinder regardless of hp will probably drag the back end down enough to put your scuppers just underwater. With an older 2 stroke, much lighter, it would probably self bail when the boat was new but if theres water in the stringer foam it still might be a little too low to self bail. Ping Pong ball scuppers or duck bill scuppers do a pretty good job of keeping the water out but would be a little concerned if you're planning on keeping the boat in the water all the time.

[RickK]

Ditto with what dbiscayne said.  The original boat was usually outfitted with a 70-85hp (some had twin 70s). By '75 they were capable of a 130hp.
The early models had the scuppers/deck drains down in the bottom of the trough below the engine. I usually left a plug in mine unless I could get on plane and then pulled the plug(s) to drain what was in the trough. Keep the engine as light as possible, the common urge is speed which requires HP which includes weight.

[tbergmann93]

Would a 50hp newer outboard be too ‘weak’ of an engine then? In an effort to reduce weight? I don’t need to go much over 25 mph.

[RickK]

I don't think you would be happy with the performance of a 50. Look for at least a 70.