# replacing rear decking - use pressure treated, pine or douglas fir?



## BIGRIGZ (Oct 2, 2007)

We have to redo the front and rear decks on a fiberglass fish-n-ski bow-rider.



The decks are inserts and not part of the hull or top-cap.



I just want it to last for several years and I'm wondering what will accomplish that?



Originally, there looks to be 3/8 plywood with a thin layer of chopped-strand fiberglass and the carpeting on top.



I'm trying to decide if:

1- I should use pressure treated plywood and cover it with carpet.

2- I should use regular pine plywood and coat it with fiberglass Resin or Thompson's water seal.

3- Bite the bullet and get some marine grade Douglas fir for $80/sheet. ouch.


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## TWINKIE6816 (Oct 10, 2007)

option 3 ALWAYS! I have found this out first hand! It will last longer! I will still coat with fiberglass though! (both sides)


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## BIGRIGZ (Oct 2, 2007)

Does anyone know if 1/2 marine grade plywood will be sufficient strength for the top deck?


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## BIGRIGZ (Oct 2, 2007)

Anyone have a good source for marine carpet????


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## choppedliver (Apr 4, 2009)

> *BIGRIGZ (5/15/2009)*We have to redo the front and rear decks on a fiberglass fish-n-ski bow-rider.
> 
> The decks are inserts and not part of the hull or top-cap.
> 
> ...


If you just wanted it to last for a *<U>few years</U>*, I would think regular pressure treated would be just fine.Especially if you coated it with fiberglass.


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## Tuna Man (Oct 2, 2007)

Bite the bullet as I think pressure treated lumber has too much moisture in it and could hamperusing adhesive for eithercarpet/glass. I used PT plywood in my jon boat and the carpet released.


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## choppedliver (Apr 4, 2009)

> *Tuna Man (5/15/2009)*Bite the bullet as I think pressure treated lumber has too much moisture in it and could hamperusing adhesive for eithercarpet/glass. I used PT plywood in my jon boat and the carpet released.


You have a point,when that pressure treated stuff is new, you can smack it with a hammer and moisture will puddle up where you hit the hammer. Maybe a few days in the sun, especially today ( whew its freakin hot )


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## BIGRIGZ (Oct 2, 2007)

Hey Ron, or anyone else....



Do you think 1/2" will be ok to stand on the rear deck?


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## Tuna Man (Oct 2, 2007)

> *BIGRIGZ (5/15/2009)*Hey Ron, or anyone else....
> 
> Do you think 1/2" will be ok to stand on the rear deck?


Depends on the size ie: length X width that is NOT braced. Look at it this way...take a full sheet and brace it on both ends and stand in the middle...ummmmm not good. Now cut a piece 1' X 1' brace and stand in the middle.....More information is needed. I used 1/2" in my jon boat, 4' wide and about 16" between supports and it was fine. Used 1 sheet, cut in quarters so it would install and touch the sides. Lasted about 8 years, needs to be replaced.


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## johnsonbeachbum (Oct 1, 2007)

Someone had 1"x3"x 12' cypress in pensacola craigslist at $3.00 each.


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## X-Shark (Oct 3, 2007)

> *Tuna Man (5/15/2009)*Bite the bullet as I think pressure treated lumber has too much moisture in it and could hamperusing adhesive for eithercarpet/glass. I used PT plywood in my jon boat and the carpet released.




Exactly!



Marine Plywood can be had at Merridith Lumber at a reasonable cost compared to other places around the country. They stock 3/8in, 1/2in and 3/4in.



Now, What is Marine Plywood?



A-B Fir Marine is what it is and has been a standard for a long time.

There are others. Okume Marine BS1088 & Meranti Marine BS1088, but you will not find them here local.



What Marine plywood is NOT is Pressure Treated. In the building trades they do call it Marine plywood, but your not building a house.





Fix it right..Fix it once. A light layer of glass cloth on the bottom side [6oz] will keep it from checking.



Heavier glass on the topside to stop and protect things that are dropped on the deck is necessary.



But remember any place you drill a hole and mount something has the potential to have water weep into it. So extra care must be made to protect from that.



That is the biggest problem....Lack of attention to detail!


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## KPTN (May 21, 2009)

I used NidaCore honey comb panels in my boat. 10mm laminated with 1708 cloth on both sides is approximately 1/2 thick, you can buy it already laminated and it is cheaper and faster. The stuff is strong, light weight, will never rot (even if you don't seal the holes) and really don't cost any more than marine grade plywood. I spanned some pretty large areas but i filled the core with 2 part foam and it is solid.

I would fix it to the best of my ability and my budget, you never know what the future holds.


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## X-Shark (Oct 3, 2007)

With cores like Nidacore, there needs to be special attention paid to how stuff is mounted. It will not hold screws.



Even if you were thru bolting this methiod should be used.



http://bertram31.com/proj/tips/sleeving.htm


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## jim t (Sep 30, 2007)

How about 3/8" or 1/2"HDPE?... Expensive,a bit heavier maybe,but it will last forever.

Jim


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## X-Shark (Oct 3, 2007)

HDPE [High-density polyethylene] is what Starboard is..



Nope..Nothing sticks to it.


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## jim t (Sep 30, 2007)

> *X-Shark (5/22/2009)*HDPE [High-density polyethylene] is what Starboard is..
> 
> Nope..Nothing sticks to it.


That makes sense...

Thanks,

Jim


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## MULLET HUNTER (Oct 3, 2007)

no doubt, nida-core is by far the lightest and most econimical.


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