Chris Reid
New member
Can anyone tell me if sanded fir plywood would be a good choice for building a marshboat, and how well will it hold epoxy and fiberglass?
sanded fir plywood
- Thread starter Chris Reid
- Start date
John L
Well-known member
Chris,
It will hold epoxy and fiberglass. However, regular fir plywood will have a lot of voids in it and would not be my first choice for a build. Your better off using quailty materials so you will have a problem free build. Use marine grade plywood if it's available. In my opinion it's not worth the time and effort to use anything less if you want a boat that will last.
It will hold epoxy and fiberglass. However, regular fir plywood will have a lot of voids in it and would not be my first choice for a build. Your better off using quailty materials so you will have a problem free build. Use marine grade plywood if it's available. In my opinion it's not worth the time and effort to use anything less if you want a boat that will last.
Something to think about. All fir plywood these days check over time. Checking if you aren't familiar is cracking/splitting along the grain of the face veneers. This happens even if you put epoxy on it and eliminates the benefit of epoxy somewhat. Typically, people glass the ply and this protects the face plys from checking, this has to be done in and out. Chuck is right on, it depends on the boat - how much work you are putting into it and is it worth it to use fir vs a marine plywood less apt to check. Is the boat simple and slapped together and it wouldnt' kill you for it to rot away in a few years or is it going to be a masterpiece that will kill you when it starts to fall apart? Can you dry it out between trips and keep it out of the weather? What is the construction, can you get the water out of it between trips easily enought to actually do it.
For me, my time and effort is worth more than the money to upgrade plywood. THe first boat I built was a pirogue I built out of marine doug fir, I glassed it inside and out because I knew I had to because fo the checking, but what a pain in the ass to glass the inside. To do it again I woudl have used meranti and glassed the outside and the floor fo the boat to protect it from the wear fo boots. Had I made the boat and slapped it together and not glassed the inside, it probably woudl have fallen apart by now, but again it doesn't matter since I dont' use it. Six of one half dozen the other way....
Jon Yenulonis
Well-known member
Just an idea. (read into this-what I did)
I used high grade marine plywood on the hull of my Zack Taylor Plywood Sneak Box. Taped the seams, then glassed the entire bottom as in the plans. BUT, I used sanded fir plywood for the decking. I did not glass that because I wanted to maintain the "wood" look and feel of the boat. (I could say cost too, as Fir is only about a third the price as the marine ply).
Jon
I used high grade marine plywood on the hull of my Zack Taylor Plywood Sneak Box. Taped the seams, then glassed the entire bottom as in the plans. BUT, I used sanded fir plywood for the decking. I did not glass that because I wanted to maintain the "wood" look and feel of the boat. (I could say cost too, as Fir is only about a third the price as the marine ply).
Jon
Bob B
Well-known member
Chris,
I built a Kara over 11 years ago out of AC fir ply. Covered the outside with cloth and painted the inside with latex house paint. It rides the rafters in my garage about 8 months of the year and is outside with a cover the other 4.
Still hunts and looks like the day I built it.
I built a few skiffs out of AC ply after seeing the dozens of similar ones built by a local builder. They were never sheathed with cloth and most lasted way longer than 10 years.
For what it is worth, build it and see what happens. It wont sink and you can build the next one in 8 to 10 years if you have problems.
Not every lumber yard has marine and if they do it is a pile of money. Way to much for a marsh boat if I am building it.
If you are talking about a serious build with a lot of detail and hours the marine starts to make sense but not for a simple project like a marsh boat.
Have fun and see if you like building boats.
Bob
I built a Kara over 11 years ago out of AC fir ply. Covered the outside with cloth and painted the inside with latex house paint. It rides the rafters in my garage about 8 months of the year and is outside with a cover the other 4.
Still hunts and looks like the day I built it.
I built a few skiffs out of AC ply after seeing the dozens of similar ones built by a local builder. They were never sheathed with cloth and most lasted way longer than 10 years.
For what it is worth, build it and see what happens. It wont sink and you can build the next one in 8 to 10 years if you have problems.
Not every lumber yard has marine and if they do it is a pile of money. Way to much for a marsh boat if I am building it.
If you are talking about a serious build with a lot of detail and hours the marine starts to make sense but not for a simple project like a marsh boat.
Have fun and see if you like building boats.
Bob
Wispete
Well-known member
Chris a stated before fir will check. Get marine ply if you can. The next ply if you can get it is Baltic birch. It has no voids but has to be encapsulated in epoxy. the third ply to get is what they use for underlayment for floors. They kind to look for has at least five layers in 1/4" ply. Also encapsulate in epoxy. If on a tight budget and you can't get epoxy. Use three coats of oil primer and then three coats of oil enamel. The important thing is to prevent water from getting to the wood.