Stringer / deck replacement

[trendsetter]

If there is water getting under the floor then it will eventually rot the wood. It's a matter of how well the original stringers and floor were sealed. But if there is wood in there it will rot.

If there are no soft spots on the deck or transom then that is a good sign; but there could still be rot under the floor. Only way to tell is to remove part or all of the floor and check. You could possibly check with a drill if you find on the deck there are screws that follow a longitudinal pattern then they are probably screwed into the stringers. Remove the screws and check for rotted wood in the screw holes. Also you could drill a shallow hole into the stringers and check the wood as well.

Just be careful not to drill to deep or into the hull. Always reseal any new holes with 3m 5200.

As for your leak, yes it's better to seal from the inside out but sealing from the outside is better than nothing. Use 3m 5200 to seal and holes below the water line if you don't have or want to work with fiberglass.

 

[fish stalker]

Which comes back to my thought of using plastic wood. Do people use this at all? Ive made some fences for clients and now into boating thought its the perfect material for stringers.

 

[trendsetter]

Which comes back to my thought of using plastic wood. Do people use this at all? Ive made some fences for clients and now into boating thought its the perfect material for stringers.

I've never heard of people using plastic wood. There are pour in products like seacast that can be used to make the stringers and transom. It's far more expensive than wood though. Not sure if the plastic wood would flex the same way as the natural stuff. Would it shatter or snap under stress?

Wood is the best option, that's why pretty much every boat out there is built with it. If done properly and the boat is maintained it will last indefinitely. The original stringers in my boat were 41 years old when I replaced them.

 

[fish stalker]

Its not a widely known and available product and of course people stick with what they know (wood). Its flexy but strong, uv restraint, water resistant. Ive had 2x2's buried in the ground as path stakes for years and they dont show signs of brittleness. Im actually not sure the company is still around. Symtil or somthing.. Im needing to redo stringers so was wondering what to do as well.

 

[trendsetter]

Sounds interesting and sure it might be a good option. I would still wonder about it's flexibility and breaking point. If the plastic is less flexible than the fiberglass all the pressure will be on the plastic and it might snap under load. Whereas wood is more flexible than the glass and will flex first then the rest of the pressure is transferred to the glass.

Some people make stringers out of styrofoam. However when you use a weaker material like that you need to increase the amount of fiberglass to compensate. Since fiberglass and resin is so much more expensive it usually doesn't make sense economically.

I'd just stick with exterior grade plywood and epoxy for the stringers. If you do it right they will outlast you.

 

[chris73]

Don't forget that wood will even rot if dry. It's organical matter and degrades over time. Moisture of course accelerates the process as mold and fungi thrive. When I cut my 30 year old stringers out (2x10 fir) there were parts that were heavily affected by dry rot. Never even got wet.

I used a kind of plastic wood to bed the new stingers and fit them tightly and evenly to the hull. Works great. But it's expensive stuff that I do not want to use for forming entire stringers. As trendsetter said, wood has the right properties and is cheap. Just does not last forever.

I found out that my stingers are due when I drilled a few holes in to attached a fuel line to it. Interestingly, my stingers were not evenly rotten, a foot wide section was almost completely gone, then 2-3 feet very solid again, then another compromised part... Basically the stringers did not create a continuous beam from front to back anymore.

Only way to tell is doing some damage in form of holes or cuts. And as I said, poking a few holes in one place does not mean it's ok throughout. You will have to check front to back to be sure. I would make a bet that almost all wooden stringers > 30 years old are due. If I had to estimate a deterioration curve I'd say that an average maintained and stored boat 10 years or younger will have close to 100% integrity of the wood structure. At 15 years maybe 85%, at 20 years maybe 65%, at 25 years less than 40%.

 

[Sangster21]

Thanks for the replies, I have a couple of diamond blades for my angle grinder, and will try that for cutting the fibreglass. I hope that works well, as I also bought a door jamb blade for angle grinder which would be a heck of a lot more dangerous to use! I know it will be a ton of work, but I do like a good project. I have frame off restored an old Toyota Landcruiser, total gut on a 1940's house, built my own garage...... on and on. I like to be busy. I am capable of doing all the work so I don't have to pay for labour. I plan on building a fishing boat not a party boat, kind of a pick up truck for the water. Power is the old reliable Chev I6, with a mercruiser leg. Any good suggestions to make an inboard more fishy are welcome. For example where is best location to put downriggers, net storage solutions, transom storage etc. Thanks.

 

[fish stalker]

Found them! http://www.syntalproducts.com/content/altwood_lumber/features_benefits.asp More expensive then wood but not outrageous.

 

[wolf]

IF you use kiln dried wood you wont get dry rot it need a 20% moisture content for dry rot to form, rot need to things a bit of mosture and air once sealed it ususally good for many years thats why almost every boat has wood stringers , trust me if you do it right it will outlast you LOL

AS im sure in 10 years or less you will get twofootitis is a very well know disease effects many a boater and fisherman and is sometimes contagious be carefull it gets almost everyone and they have found no cure for it.

Good luck Wolf

 

[Hoochiebob]

Prior to me starting on my own stringer and deck replacement, a friend of mine lent me a book to read. "The Fiberglass boat repair manual" by Allen H. Vaitses. There is a lot of good information, with tips and techniques that really improved the quality of my installation. It also compares the materials you can use, from fiberglass cloth to gelcoat, to best suit your needs and budget.
When my project was done my boat handled much better and I gained 3 mph on my top end , and all the hard work is rewarded every time I step into my boat.
Good luck on your project!

 

[danthewire]

I found this site awhile ago, had a lot of info that may be helpful.
I'll give you a link, search around there, its pretty good.
http://www.classicmako.com/forum/topic.asp?TOPIC_ID=38800
Dan.

 

[Sangster21]

Prior to me starting on my own stringer and deck replacement, a friend of mine lent me a book to read. "The Fiberglass boat repair manual" by Allen H. Vaitses. There is a lot of good information, with tips and techniques that really improved the quality of my installation. It also compares the materials you can use, from fiberglass cloth to gelcoat, to best suit your needs and budget.
When my project was done my boat handled much better and I gained 3 mph on my top end , and all the hard work is rewarded every time I step into my boat.
Good luck on your project!

I have the same book myself, bought it a couple of years ago... I must have been psychic or something. Good info in the book plus a ton of info out there on the world wide web.
Alan

 

[Foxsea]

I replaced the floor, stringers and transom in an old 17' GlasPar about 15 years ago. It is a filthy job, cutting the old stuff away - the wood was totally rotten. I also removed many garbage bags full of old, water-logged buoyancy foam. As many have suggested here, I used an old circular saw to cut close to the hull and then an angle grinder with masonry discs to get right up close to the hull. I replaced all the wood with pressure-treated lumber and plywood - the PWF stuff they use for buried wood foundations on the prairies. I ordered the 3/4" ply from a local lumber yard. Where I had machined the edges, I soaked the wood with the "end-cut" preservative. I used polyurethane (Sikaflex) to bed and contour all the plywood edges and the lumber stringers to the hull. The fiberglassing was pretty easy, once the ugly tear-out and wood-work was done. I used hypalon, roll-on deck coating to finish the floor.

It all worked out well but took a lot of time. I sold the boat shortly afterward. At the end of the day, I spent more money on that fix than the old boat was worth. And, I would much rather be out fishing in a storm than ever spend the time doing that job again! 20-20: I'd just give it away to someone else looking for a project, a money pit and an education. Unless it's a Gar Wood, an old boat is an old boat...

 

[Foxsea]

I'd just stick with exterior grade plywood and epoxy ... If you do it right they will outlast you.

Pressure-treated lumber (for foundations - not the decking stuff) is designed to be buried and will outlast all of us!

 

[Sculpin]

I replaced the floor, stringers and transom in an old 17' GlasPar about 15 years ago. It is a filthy job, cutting the old stuff away - the wood was totally rotten. I also removed many garbage bags full of old, water-logged buoyancy foam. As many have suggested here, I used an old circular saw to cut close to the hull and then an angle grinder with masonry discs to get right up close to the hull. I replaced all the wood with pressure-treated lumber and plywood - the PWF stuff they use for buried wood foundations on the prairies. I ordered the 3/4" ply from a local lumber yard. Where I had machined the edges, I soaked the wood with the "end-cut" preservative. I used polyurethane (Sikaflex) to bed and contour all the plywood edges and the lumber stringers to the hull. The fiberglassing was pretty easy, once the ugly tear-out and wood-work was done. I used hypalon, roll-on deck coating to finish the floor.

It all worked out well but took a lot of time. I sold the boat shortly afterward. At the end of the day, I spent more money on that fix than the old boat was worth. And, I would much rather be out fishing in a storm than ever spend the time doing that job again! 20-20: I'd just give it away to someone else looking for a project, a money pit and an education. Unless it's a Gar Wood, an old boat is an old boat...

Just about everything in this post leans towards why folk's should look to aluminum for there choice of boat material. Just sayin'. I'm on an aluminum crusade.

 

[Foxsea]

Just about everything in this post leans towards why folk's should look to aluminum for there choice of boat material. Just sayin'. I'm on an aluminum crusade.

No argument here - when I win the lottery (or I'm divorced again and living in a cheap apartment), I'll be offshore, fishing in a 26' Lifetimer! (local brand loyalty)
In the meantime, I'll stay married and happily offshore fishing in my 26' glass boat.

 

[Sculpin]

No argument here - when I win the lottery (or I'm divorced again and living in a cheap apartment), I'll be offshore, fishing in a 26' Lifetimer! (local brand loyalty)
In the meantime, I'll stay married and happily offshore fishing in my 26' glass boat.

Lol. I was just having some fun Foxsea. Aluminum's are not that expensive if you look around. They do last a lifetime if looked after.

 

[Foxsea]

Lol. I was just having some fun Foxsea. Aluminum's are not that expensive if you look around. They do last a lifetime if looked after.

Right-on! I like your sense of humour. I went out with a buddy on his Kingfisher - loved that!

 

[Sangster21]

Sangster rebuild

I have done a fair bit of work in the last little while working on the boat. Totally gutted and ground to bare hull. Yup grinding fiberglass sucks pretty bad. Glad to have the tear out done! Need to do another dump run to empty out the truck, vacuum the inside of the boat and start building a transom. Should be more fun than working an angle grinder.

 

[danthewire]

Nice looking work.
Keep us posted.
Dan