1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

[mjboater]

Bought an 89 Grumman 14' Aluminum Boat. Took out last year no problems but it need TLC. Decided to put new floors in it this year and while I've completed many home and auto restorations this is my first boat project and I'd like to do it right. Since I dont have experience in this area I was hoping I could get some advice. Today I picked up a sheet of 3/4 marine grade A-B plywood. Nice stuff but sheet cost $90. From what I've heard Marine Grade is way to go. Pulled old floor decking out in the spring but I left boat uncovered so it was kinda dirty inside plus, it seems that the foam that was in there had years of crud in it as the foam affected drainage it seems. I[ve put some pics in so you can see foam, crud etc... After cleaning out old floatation foam and hosing down looks pretty good. My plan is now to do as follows...

1. Test boat for leaks by filling with water?
2. Use gluvit on the seams?
3. Add foam (pink sheets or blue sheet? from Home Depot?) Not sure what to use here. I do have flotation blocks under both benches where seats go. Should I use more foam to replaced nasty stuff I pulled out?
4. Cut marine grade ply to fit, install carpet to cut pieces with adhesive and monel staples.
5. Secure sheets to stringers with stainless screws.

Should I paint interior too? Any recommendation there. I heard Rustoleum makes an aluminum spray thats pretty nice.

6. Cut marine grade ply to cover livewell, and storage comparments.

Again this is my first boat project and any advice from you guys is really appreciated thanks!!!!! MJBoater








Wha

 

[jigngrub]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

What kind of marine grade plywood did you get?

Testing your boat for leaks is good, if you have leaking rivets you can replace them like this:

http://www.youtube.com/watch?v=L0MA1-5NXjs&feature=related

Then clean the boat out good (pressure wash) let dry and apply gluvit to the interior seams.

Add pink or blue sheet foam where old foam was removed.

Painting the interior would make it look really nice, Rustoleum marine grade paint is used by several members here.

 

[CheapboatKev]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

Welcome,
You dont have to use Rust marine grade at all.
Rustoleum in quart cans will brush or roll on. Plus even a 14 ftr will take a ton of them and you wont get the coverage that brushing or rolling would.

 

[Racingman24]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

Wow. you might as well be working on my boat. From the outside they look almost the same. [Hull Shape and such]

I've got a 14' Alumacraft that I'm actually nearing completion on, where I did the same as you're looking at doing....and way more.

Have a gander at the thread...http://forums.iboats.com/showthread.php?t=377686&highlight=racingman+tinny....And I'm sure it answer at least some of your questions.

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

Wow. you might as well be working on my boat. From the outside they look almost the same. [Hull Shape and such]

I've got a 14' Alumacraft that I'm actually nearing completion on, where I did the same as you're looking at doing....and way more.

Have a gander at the thread...http://forums.iboats.com/showthread.php?t=377686&highlight=racingman+tinny....And I'm sure it answer at least some of your questions.

I noticed some have had to do alot of work on the transom. From what I see on the outside and as shown in the pictures, I think mine looks good. Am I missing something? I dont see any rotted wood on the transom but then again I see no wood at all. Is wood under the aluminum that I cant see? Thanks

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

I bought a 4X8 sheet of 3/4" marine grade plywood (FIR) Cost $92 per sheet but I heard of all the interaction between p.t. plywood and aluminum etc.... so I went this route. The floor I pullled up was 3/4 but I dont know if it was marine grade or not.

 

[jigngrub]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

I bought a 4X8 sheet of 3/4" marine grade plywood (FIR) Cost $92 per sheet but I heard of all the interaction between p.t. plywood and aluminum etc.... so I went this route. The floor I pullled up was 3/4 but I dont know if it was marine grade or not.

Not all pressure treated plywood is bad, as a matter of fact this PT plywood is manufactured mainly for the boating industry.

http://www.pontoonstuff.com/pontoon-boat/144-marine-plywood.asp

$65 a sheet and a lifetime warranty isn't a bad deal.

You don't have to worry about sealing it with anything or fasteners penetrating a protective barrier.

 

[oops!]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

take the marine grade plywood back......

this is just a deck on a tinny........the marine grade is used for a different purpose than what you are using it for.
marine grade is ment for the hull of a wooden hulled boat.......not the deck on a tinny.

standard grade exterior plywood is more than enough, if you glass both sides.....it willl last 40 years in a tinny.

you can use the 2 part pour in foam or whatever you want for floatation.....

to test it for leaks....rip out the deck and existing foam......and take it to the lake !!!!!
add some weight.....and look for leaks.

you can gluvit on the seams form the inside just for fun and insurance.

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

Since last update, I've done some more work but still havent replaced flooring. Cut out floor pieces using cardboard templates. Also been getting all things needed together over the winter so I can get started again in Spring. Well Spring here... Time to get goin! Here's some more pictures of where I am at now. Few concerns I have is about the stringers. Near the middle of the boat, one of the stringers is corroded and worn thin. If you open the picture you can see right in front of the floor piece I dry-fit that the stringer is rotted through. Has holes in it. Do I have to replace who stringer end to end or just replaced damaged piece. Maybe add a 4 inch pc where the rot is? Not too familiar with rivets but... I have hard rivets should be rebucked? I plan to check for loose ones, rebuck them, lightly sand aluminum the floor where I can and apply gluvit over the rivets and seams. Where the pour in foam used to be its bare aluminum and has oxidized a little over the winter. Guess I need to give that a good cleaning before the gluvit? Not sure what to use though. Was wondering if anyone has advice on how to proceed. Taking the winter off defintely made me rusty and given my experience I could definitely use some pointers before I dive in again thanks!!!!!

 

[jigngrub]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

It's hard to tell about your stringer from the pics you posted, but you can patch that thing right up with some 1/16" thick aluminum and some blind (pop) rivets. I'd make it a 2' long patch, 12" on each side of the bad spot for strength and on each side of the stringer and the top too.

What do you plan on sealing your decking with?

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

It's hard to tell about your stringer from the pics you posted, but you can patch that thing right up with some 1/16" thick aluminum and some blind (pop) rivets. I'd make it a 2' long patch, 12" on each side of the bad spot for strength and on each side of the stringer and the top too.

What do you plan on sealing your decking with?

I cut my floor pcs out of 3/4 marine grade. Prob overkill and could have used exterior grade but initially I though that would be best way to go. Planned on attaching floor to stringers using stainless screws that I salvaged from old floor. Thinking I'll use Roberts 6700 indoor outdoor adhesive from Home Depot.

http://www.homedepot.com/buy/floori...indoor-and-outdoor-carpet-adhesive-63955.html

Picked up Cabelas Vinyl Flooring last year. Pretty much same as this stuff.

http://www.cabelas.com/product/Boat..._l=SBC;cat104794380;cat104711580;cat104672880

Was thinking of gluing it to the decking. Then use some kind of marine grade carpet on two benches and also on covers to live well and storage compartment.

http://www.cabelas.com/product/Boat..._l=SBC;cat104794380;cat104711580;cat104254380


I have blue/gray seats I ordered from Cabelas last year too.

http://www.cabelas.com/product/Boat..._l=SBC;cat104794380;cat104705280;cat104341680

 

[Woodonglass]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

IMHO, You need to coat the wood with either 2 coats of epoxy, or Polyester Resin and Fiberglass mat if you want it to last long term. Need to pay close attention to sealing the edges. Thats the most critical area for water penetration. You could use other methods but either of these will ensure longevity of the deck/sole.

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

IMHO, You need to coat the wood with either 2 coats of epoxy, or Polyester Resin and Fiberglass mat if you want it to last long term. Need to pay close attention to sealing the edges. Thats the most critical area for water penetration. You could use other methods but either of these will ensure longevity of the deck/sole.

Would I coat the wood on both sides? 2 coats of epoxy? Is that easy to apply? Any recommendation of which product to use. Ease of application helps as I'm literally working in my driveway and dont have access to a garage to work indoors. Temps now outside low as 30 high as 75 degrees. Could affect application. thanks!!!!!

 

[jigngrub]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

Would I coat the wood on both sides? 2 coats of epoxy? Is that easy to apply? Any recommendation of which product to use. Ease of application helps as I'm literally working in my driveway and dont have access to a garage to work indoors. Temps now outside low as 30 high as 75 degrees. Could affect application. thanks!!!!!

I'd go with the epoxy if I were you, you spent a lot of money on that expensive wood and I know you want it to last.

The epoxy is easy to apply and there are different mixes for different working temperatures.

A lot of folks on here buy their epoxy from here:

http://www.uscomposites.com/epoxy.html#epoxhard

Since you're working in cooler weather you may want to use the 4:1 fast mix. Buy the pumps too for easy measuring. You should buy enough for 4 coats, I used a 1/2 gallon kit on my decking and had a little left over.

I coated the topside and edges only on my decking, my thinking is that the bottom rarely if ever gets wet and having it uncoated will let the plywood breathe and wick any moisture away that may penetrate through the deck fasteners or any other small/tiny leaks. I feel that coating both sides and edges will trap any moisture that happens to get into the decking.

For your vinyl, I suggest wrapping your deck pieces individually and then installing it with the fasteners exposed. This way you can remove your decking if you ever have to make below deck repairs and not ruin your nice vinyl job.

For deck fasteners I suggest blind (pop) rivets, screws can and will twist the vinyl upon installation. If you're interested in the rivets I have a link to a supplier.

This is how my vinyl job looked last year when I finished it.

http://forums.iboats.com/showthread.php?t=509163

 

[mjboater]

Re: 1989 Grumman 14' Aluminum Boat Floor and Foam Replacement

I'd go with the epoxy if I were you, you spent a lot of money on that expensive wood and I know you want it to last.

The epoxy is easy to apply and there are different mixes for different working temperatures.

A lot of folks on here buy their epoxy from here:

http://www.uscomposites.com/epoxy.html#epoxhard

Since you're working in cooler weather you may want to use the 4:1 fast mix. Buy the pumps too for easy measuring. You should buy enough for 4 coats, I used a 1/2 gallon kit on my decking and had a little left over.

I coated the topside and edges only on my decking, my thinking is that the bottom rarely if ever gets wet and having it uncoated will let the plywood breathe and wick any moisture away that may penetrate through the deck fasteners or any other small/tiny leaks. I feel that coating both sides and edges will trap any moisture that happens to get into the decking.

For your vinyl, I suggest wrapping your deck pieces individually and then installing it with the fasteners exposed. This way you can remove your decking if you ever have to make below deck repairs and not ruin your nice vinyl job.

For deck fasteners I suggest blind (pop) rivets, screws can and will twist the vinyl upon installation. If you're interested in the rivets I have a link to a supplier.

This is how my vinyl job looked last year when I finished it.

http://forums.iboats.com/showthread.php?t=509163

Experience.... is priceless. I cant thank you all enough for the guidance... Am looking forward to putting it all together again as the fish are biting!!! Dont want to be stuck on-shore for too much longer