Wet boat

[lckstckn2smknbrls]

I use my jon for duck hunting and it lives outside year round. I don't have any carpeting just exterior grade plywood for the deck and floors that get painted with exterior latex every few years. It does get tarped in the winter to keep the snow and ice out.

 

[tccanoe]

Back to the first thread. Getting the carpet dry. Try putting a dehumidfier in the boat, draining it to the garage floor then putting a tarp over the whole thing. Something along that line. You don't have to prop the tarp up much because the less area to dry the faster it will work. What do you think? P.S. This is my 50th Post. Do I get a watch or something?

 

[lckstckn2smknbrls]

Congratulations you get the or Something.

 

[WhiteMoose]

lol thanks for the replies. We don't have a dehumidifier, and I don't think the wife will let me buy one just for drying out the boat. I'll just drag it outside when I get home and plan on replacing the wood in a few years I guess. I am going to keep my eyes open for some old alumn. road signs to use as decking next time.

 

[ihavenoideawhattoput]

lol thanks for the replies. We don't have a dehumidifier, and I don't think the wife will let me buy one just for drying out the boat. I'll just drag it outside when I get home and plan on replacing the wood in a few years I guess. I am going to keep my eyes open for some old alumn. road signs to use as decking next time.

ROAD SIGNS, I like it, wonder why I never thought of that! I see them everywhere!

You could also use the fans and and the tarp to make a cheap dehumidifier, Cover the boat and let the fans draw the moisture out from under the tarp, sorry for the tread jack back there.

 

[bassboy1]

Alot of people think marine plywood is different well i got news it is not that much different then good plywood at lowes or home depot...

The difference between reg plywood and marine is the glue they use on the wood as it is stronger and holds together alot better.

Uh, no.

For the record, the glue used in marine grade plywood is the SAME glue used in the CHEAPEST plywood available at Lowes and Home Depot. Basically, there are two adhesives used in all plywoods. An interior, and an exterior grade. The cheap, knarly, knotty plywood available at the home centers is an exterior grade sheathing, designed to be bought in bulk, sheath a wall or roof, then covered up.

The interior grade ply, which is actually a step up in cost, uses an interior grade glue, which we would deem not waterproof. This interior grade usually lacks voids on the outer faces, making it useful for cabinet and furniture work. Those little football shaped plugs in the plywood are where knots and voids were punched out, and replaced with a plug of good wood. Generally, these plugs will only be on the outer plys. Ever cut a piece of plywood, and found some openings in your cut edge? Those are voids in the inner plys, which don't have plugs.

Now, marine grade, first of all, does not have a grade lower than B, and most is A which means that it will not have any voids throughout all the plys. Thus, everywhere a knot or bad spot would be, there is one of those little footballs. These voids are what cause poor adhesion, AND give water a place to accumulate (how it gets in there, I don't know. Water will find it's way into ANYTHING you don't want it to - Murphy musta had some weird spiritual connection with water, or something. :roll: ). Furthermore, marine grade often has a greater number of thinner plys, rather than a few thicker ones.

The other difference in marine grade, is the type of wood. Most exterior plywoods are pine. Many interior plys can be gotten with a hardwood. Marine grade is usually made of a fir, often Douglas fir, or Western larch.

So yes, there are a LOT of differences between marine grade, and a cheap plywood. However, the glue is about the only thing that is NOT a difference.

Personally, I wouldn't spend the money on marine grade to build a deck on a tin rig. However, if I was constructing a plywood hull, I would spring for the marine grade. If the hull is going to be pounding through the water, I don't want interior voids. Furthermore, I would much rather have the higher quality thinner plys, as opposed to the thicker ones.

One more thing, boater, is a synthetic water sealer better than a conventional water sealer? :lol:

 

[Waterwings]

"From Professor Gene Wengert, Sawing and Drying forum technical advisor
There are two adhesives, interior (which does not stand up to wetting) and exterior (which is not affected by long term wetting and would be called waterproof). Marine grade uses exterior adhesive, which is the same adhesive as used in the cheap CD-X plywood or any other exterior grade or "interior grade with exterior glue" plywood.
With marine grade, the lowest grade veneer is "B", which means that there will be no serious voids on the surface and interior plies. It is the voids that cause poor adhesion! So, marine grade will have good adhesion throughout the lamination. Also, marine grade can be cut without getting a void in one laminate on a freshly cut edge. The edges will be totally solid. The two species used for marine grade are Douglas fir and western larch, although I have seen keruing and other species used in a product called marine grade. You can get the same performance from panels such as exterior AC in most cases.

Marine grade has no natural decay resistance. It has no chemicals added to enhance decay resistance, unless it has been subsequently pressure treated (= $$$). Marine grade has no special waterproofing in or on the wood.

If you do not get the wood wet very often and if it is sealed, as you state, there is no difference in performance indeed by using a different, less expensive grade and species. Note that most interior grade panels do not use exterior adhesives. But if the plywood seldom gets wet, the interior adhesive will be just fine."

Cut & pasted from: https://www.woodweb.com/knowledge_base/Marine_Plywood_Versus_Interior_Plywood.html

 

[Waterwings]

I read the article, but also right above it there is a response that the glue is also different in marine plywood to so i guess to some extent the people were right in what they told me.This was also written above the article u put here.

Forum)
From contributor H:
Exterior grade is not the same as waterproof. I believe the glue used in marine grade ply is different. Another difference is the amount of void allowed in the cores of the plywood. Voids are where moisture can get trapped and are weak spots in the sheet. Marine plywood is made entirely of Douglas fir or western larch. Glue is completely waterproof. Grading of all plys is far better.

Contributor H states he believes it's different. Implying he's not sure. :wink:

 

[Waterwings]

yep, 100's of sites talking about the plywoods and glues.

 

[perchin]

I must of missed something :-? Boater1234, you used a stain.... It is suppossed to penetrate, hence change the color of the wood, it would be wise of you to now seal it from the elements. Oh yeah, and NO I'm not trying to start anything, so please don't try to make it seem like I am.

Stain----- used to change the apperance of wood (most always color)

Sealer---- used to protect wood from the elements of mother nature.

I'm not making this stuff up... Just google what stain does for wood once. Then google what ANY sealer does for wood once..... I'd bet money on the sealer is better for wood than stain.

Most of those say it won't grey... meaning it will sustain its color. They can most of the time say it won't cause water damage, because it was intendid to be used on PT wood (like a deck or fence.)

 

[island fever]

Here is the plywood I will use. It is Waterproof construction/Architectual grade plywood made for concrete formwork. You can get it at any major construction supplier.

Its called Finnform and is phenetic resen coated but it too has to be sealed when cut or penetrated...heres what the manufacturer recomends.

Linky: Finnform Pywood Specs

FinnForm Technical Bulletin
FinnForm is a superior product specifically designed for concrete forming. Consistent end-use results are not only dependent on proper form design but also of equal importance on proper care and useage. In this technical bulletin, we review and detail those steps necessary to insure proper care and storage of FinnForm.

MOISTURE PENETRATION - SEALING
FinnForm, as in any other forming plywood, if not properly sealed can absorb water and moisture which could cause the panel to swell unevenly (thicken) in the area of moisture penetration. This swelling although usually less than 1/32" can cause a slight indentation in the concrete.

To prevent moisture penetration it is important that all recut FinnForm edges, all penetrations of the phenolic impregnated faces by fastening devices (nails, screws, header teks, etc.) and any other face damage, be properly sealed or resealed where required.

a. Areas to be Sealed
All recut edges and all penetrations made in FinnForm plywood for attaching to the backup must be sealed to prevent moistture penetration. If not properly sealed, moisture may cause swelling along the recut edges and around tie, bolt, nail or screw holes.NOTE: FinnForm plywood has edges completely sealed at the mill. However, in some cases, the mill applied sealer is scraped off due to shipment handling damage. It is, therefore, important to inspect all panels prior to use. (If the edge sealer has been damaged, the edge area effected should be resealed prior to use.) In fact it is recommended that all edges (even factory sealed) be resealed before use, since minor handling damage may not be visible to the eye.

Improper care and storage can also cause heavy scars in the panel face thereby removing the phenolic plastic impregnation of the outer plies. Moisture penetration will also occur in these areas if not properly sealed prior to use.

If swelling has occurrred, allow the panel to dry before applying any sealers, otherwise the moisture will be permanently trapped in the plywood giving a deviation from the normal face plane.

In addition, it is also recommended, when stripping FinnForm from the forms after use, that all sealed areas be inspected and resealed where required prior to storage or reuse.

b. Recommended Types of Sealers
A variety of water repellent sealers are effective. Among those that have proven useful for keeping moisture out of FinnForm are:

1.Urethane Sealers (Exterior)
2.Epoxy Paint (Waterless)
3.100% Acrylic Resins Paint
NOTE: To insure proper application of sealers, consult the sealer instructions or the sealer manufacturer directly.

CUTTING AND FASTENING
There are a few installation aids that will facilitate the cutting and fastening of FinnForm:

a. Cutting
FinnForm plywood can be cut readily with any sharp saw blade. However, if a large amount of mill work is anticipated, carbide tip saw blades have been the most efficient and economical. Any saw that heels, can cause splintering of either or both faces. FinnForm can be cut with hand held circle saws (skil type). However for high quality form work, table type saws have been the most proficient. When drilling tie holes the best method has been to use a hole saw. If this is not possible, it is suggested that, as with any laminated product, it is best to use some method of back-up blocking to prevent excessive splintering of the back side of the panel.

b. Fastening
Where the surface requirements will allow the use of nails, it is recommended that common rather than box nails be used, since they will hold into the back-up material more effectively. Experience has shown that it is economical to use more sophisticated fastening devices because forms made with FinnForm faces have a greater effective re-use expectancy. Such devices as screw nails, ring shank nails, recessed flat head screws, header teks, split rivets, have been used to fasten FinnForm to the back up material. Blind fastening devices, etc., have been used to fasten FinnForm to back-up material where contractors needed a fair faced concrete. This is feasible because the withdrawal loads of fastening devices (screws, nails, etc.) are much higher in FinnForm than in most other plywoods.

 

[tccanoe]

Once you treat the wood with something like the Olympic, then cover the wood with a good quality glue, then cover the wood with a good quality MARINE carpet, then cover the boat with a good quality cover, how long do you think that wood is going to last. Years and years. It's a combenation of efforts not just one step.