Wednesday, March 12, 2008

Prime and Paint Question

I am building with a modified stitch and glue, I have used PL Premium polyurethane construction adhesive for my seams, stuff is strong, waterproof and I found once fully cured the plywood will fail way before the glue. It will take paint according to manufacture.
 
now the question, all the "stitch and glue" techniques call for fiberglass tape and resin at the seems inside and outside, (more expensive than I want) and all I have found built this way are left clear coated with the resin.
 
I plan to apply two coats of exterior wood primer and paint inside and outside, do I have to apply fiberglass and resin to my plywood, this boat will be used maybe 10 times a year during camping trips and stored inside a climate controlled shop.
 
 

7 comments:

  1. RJ, what you have done is perfectly acceptable (IMO) and you will probably have many years of good service out of your pirogue.   Having said that, I have used "poly" glues - three different brands - and have had mixed results with the claims of being waterproof.  My personal favorite is Elmer's Polyurethane.  I was not real impressed with the Gorilla brand I tried, it let go after I soaked some glued plywood for 9 hours.  I would rank the Titebond product as equal to Elmer's.   The sailboat I am currently building is ribbed with redwood and planked with 1/4" ACX plywood.  All unions and joints are glued with Elmer's poly and screwed with brass woodscrews.  I did take the extra precaution of taping and epoxying the seams along with all internal seams fileted with a sawdust/epoxy mix.  But this boat is quite hefty, even half-finished she weighs around 300 lbs. and that is without the all-steel centerboard (@ 200 lbs), decking, mast and all the attendant hardware - all of which add considerable stress to the hull.  Obviously a different situation from a lightweight plywood canoe like you are building.   Keep up on the paint coat (or varnish) and the hull should last for many years, especially as you are only putting it in the water when you are actually using it.   Please post some pictures of your project as you go.  We almost all maintain photo albums of our projects so welcome to the family and enjoy whatever you do...   Andy

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  2. Andy, Thanks for the info, sounds like a big boat, I'm thinking my next one will either be a small sail or the 11' kayak from JEM, anyhow thanks for the support and I am gonna try and attach a photo,   I am calling it a pironoe cause it is not completely flat, I did a neg 1inch on the bottom of the sides and a little angle on the front and rear stems to give flair to the sides, and lift to the front and rear of the bottom. Not sure what to call that lift.   Thankd again.

    Attachment: My pironoe.jpg

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  3. No matter how you store the boat, or how many times you use it per year, all it takes is one failure to ruin a trip. Try explaining it to your surviving children or grandchildren. Not worth the chance in my book! Will 

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  4. So you are saying a primed and painted boat put together with premuim poly glue is not a good thing?   as for children, dont have any not gonna have any.   as for painted boats haven't they been floating painted boats since noah?

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  5. Hello again. I personally would not trust glue only for my seams. A bit of resin and tape would make my pucker factor a bit less critical in a strong chop. Paint is your prerogative.  Will

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  6. Will, First and formost thank you for your opinion, I looked at your Wherry, beautiful job, wood craft like that is rarely seen in todays world. What woods did you use?   My pironoe is 11'5" long, 26 beam at floor, and 34 beam at gunnels, The purpose of the build was to have something I could lift to the top of the SUV and tie on for a weekend of camping, If a creek or lake is available I will take the Piro, I will be doing most of the paddling on slow creeks, and small lakes (5-10 acre)  for enjoyment and possibly fishing while camping.   This build was brought on by the cost and weight of fiberglass/alum canoes available comercially   Since this if the first boat I am building, and will likely be a "throwaway" if it does not suit my needs I intended to keep cost and weight to a minimum. Currently at about $55.00 at 85% done, needing only paint to float.   If it fails after 1 or 300 trips I build another, If it does not give the stability my wife will want, I throw it away, If I put it in the water for testing and it falls apart I wade ashore.   Here is a pic, will be painting this weekend.   Once again thank you for taking time to respond.   Regards, RJW

    Attachment: My pironoe.jpg

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  7. RJW, Thanks for the kind comments. I used Western Red Cedar for the hull, Alaska Yellow Cedar for the accent stripe, White Ash for the gunwales/keel/breasthook and seats, Sitka Spruce for the seat supports. My first boat was an 8ft pram, glued and screwed. I primed and then painted with Benjamin Moore glossy house paint. Worked great for many years! Be sure and post a finished picture of your boat. Looking Good! Will

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