glassing bottom on pirogue

[jdupre']

After over 45 trips in my pirogue, the combined abuses of cypress knees, logs and concrete boat ramps have taken their toll. The painted douglas fir ply is checking, especially in the high wear bow and stern areas. I'm going to glass and epoxy the bottom and sides to stop the checking and minimize the dents and scoring. I don't need strength - the boat is plenty strong just like it is- I just need to seal up the wood and stop the checking. Any suggestions on the weight of cloth I could use along with a few coats of epoxy?

Joey

 

[oldsparkey]

I like the 3.25 tight woven , offers the same strength as 6 oz glass and is a lot lighter but harder to work with according to some folks , I have never had a problem with it but I am use to working with it.

Off hand I would say the normal 6 oz would do the trick. After you have it on there , then do three light coats of the epoxy and graphite mix. That adds a lot of slippery to it and some serious protection. You could even double up the glass in the high wear areas like the bow and stern of your Pirogue with left over glass.

If you don't like that thought then there is the Teflon Paint like I have on the canoe you saw at Pipers but that stuff and it's primer will run over $80.00 bucks for the smallest container that will do 2 or 3 smaller boats.

I haven't tried it but if you can locate some Aluminum powder then it could be used with the epoxy in place of the graphite but the Fed's might be knocking on your door since that powder is used in some Illegal things .... BOMB Making.

I should not say this .... :lol: :lol: :lol: Aluminum tin foil ground up in a blender is about the same thing and that you can purchased at any grocery store , just don't get the non stick stuff for use on your boat. :roll:

Chuck.

 

[jdupre']

Chuck, I'd like to use the lightest glass that will hold down the checks. No need for added strength. I'll go with the 3.25 oz. unless I could get away with somethng lighter.

Joey

 

[oldsparkey]

Chuck, I'd like to use the lightest glass that will hold down the checks. No need for added strength. I'll go with the 3.25 oz. unless I could get away with somethng lighter.

Joey

Any lighter and it might not do what you want it to do. 3.25 is about as light as you can go and offer a lot more in strength. The epoxy and graphite over it is really an added benefit , double up on the wear areas for extra security if you want to or just be more careful on the launching and arrival back at the ramps. The ramps will wear anything down. I avoid ramps like the plague which they are , always find a softer area to put in at.

Logs , stumps and the rest of the fun things you hit when paddling in the swamps will not hurt it. Anyway they have not done any damage to my boats , not saying about me when I hit one and am balanced on it for a while and have an "O" Chit moment. :lol:

Chuck.

 

[Jimmy W]

I would think that 3 to 4 oz cloth should be all you need. West System sells the aluminum powder and that is what they recommend for abrasion resistance and graphite for low friction. You could use a mix of the two. http://www.westsystem.com/ss/product-selection-chart/

 

[jdupre']

I know I have to sand off all of the old paint, but my concern is all the nails. There's probably 150 nails attaching the chines and the bottom. Many of them are slightly countersunk and will have a bit of paint on them. Is it necessary to go down and get every last bit of paint from the nail heads and inside some of the deeper scratches?

 

[Jimmy W]

I know I have to sand off all of the old paint, but my concern is all the nails. There's probably 150 nails attaching the chines and the bottom. Many of them are slightly countersunk and will have a bit of paint on them. Is it necessary to go down and get every last bit of paint from the nail heads and inside some of the deeper scratches?

I haven't ever tried it, but I wouldn't think a bit of paint on them would hurt. They will be covered with epoxy and cloth. I would presaturate the wood with epoxy and use the epoxy (maybe with wood flour added) to try to level out the countersunk spots and deep scratches.

 

[Oyster]

What you really need is Xynole coated with Interprotect 2000E for abrasion resistance. The fabric is rougher so it does need to be faired a bit. If you go with glass, also use the Interprotect which is a mix thats already mixed the microplates, hard as a rock from Stone Mountain. Many people do use the graphite mixed in the epoxy resin, but thats ugly black and hard to sand for any type of paint. Interlux has come out with their product in white now as the grey was the standard or original color which can be left unpainted too and just fine for your use.

 

[oldsparkey]

The paint you used was it a water base or an oil base. If oil base the epoxy will not stick to it , water base there is a good Chance it might stick to it , best to get rid of all of it.

Chuck.

 

[jdupre']

Oyster, I don't think I need as much protection as the product you described. It's not like my boat has huge gouges and scrapes as we have no rocks to contend with here. I just want a fairly durable surface that won't scar just by running over a log or cypress knee. Paddling in still water all the time, I can really feel the difference a rough bottom makes in the increased drag. I plan on adding an extra layer of glass at the bow and the stern.

It is oil based paint. I guess I'll have to go down to clean metal on the nails and then fair everything in. I'm still debating on using graphite on the bottom. I'm not crazy for the look and it is probably overkill .

Joey

 

[Kayak Jack]

Joey,

The tight weave glass will probably be OK over a convex curve. It didn't like the inside of my boat at all, a concave curve. After you get a coat or two of epoxy on the glass, those coats of graphite enriched epoxy are both harder, and slipperier (new word there). My boat goes through weeds and lily pads much easier now. Also skids over obstacles easier.

 

[oldsparkey]

Joey,

The tight weave glass will probably be OK over a convex curve. It didn't like the inside of my boat at all, a concave curve. After you get a coat or two of epoxy on the glass, those coats of graphite enriched epoxy are both harder, and slipperier (new word there). My boat goes through weeds and lily pads much easier now. Also skids over obstacles easier.

Jack is telling it straight , right on point.

I had a person who was not sure if he wanted a Pirogue so when I finished the light weigh one I made he came along to try it. The bottom was epoxied and graphited. I figure only the fish will see it when I am using it if birds see it I am in deep trouble.

Anyway when he took it for a spin out in the open water of the lake and was coming back to where I was standing I hollered out to him to take it into the weeds and paddle threw then to where I was. This was a good crop of lilies and grasses ( some higher then the sides of the Pirogue ) he looked at me like I had lost all of my marbles , which is still being debated. Anyway his worried expression changed to a smile and when he got to the bank all he could say was " This thing has 4 wheel drive".

If cost is a concern , Raka has the graphite powder ... 8oz for $5.75 and it will do three boats easily.
CLC has the Brightsides Interlux paint (epoxy) and with the primer and then the paint it runs about $80.00 for both. It is slippery since it has Teflon in it.
Not sure ( never used it) about the cost on what Oyster suggested but he paddles in some rough areas so it has to be good.

Chuck.

 

[jdupre']

I like the idea of increased protection and being more slipperier . I'll probably put a coat or two of the graphite mix on. Do you have to completely seal the weave with straight epoxy before the graphite mixture or can the graphite be used to help fill the weave.

 

[oldsparkey]

You will need to epoxy saturate the bottom so some of the epoxy gets into the wood , this helps bind everything together. After it cures ( usually overnight) Lightly sand it to get rid of the whiskers , small fibers of wood that fill up with epoxy and stand up , they will snag and put runs in the glass if they aren't lightly sanded down. Then lay the glass on it and epoxy it. Usually one more coat will fill the weave and then the epoxy and graphite. You could try the epoxy and graphite as the 2 coat because it take three light coats to do the job , anyway that is how many I use.

Make sure you want the graphite on there because after is is on there it is a real S.O.B. to take off and creates quite a mess with the sander and the person doing the sanding.

BEFORE ANYTHING........ After you sand the bottom to bare wood , try a test area with the saturation and see if it lays on there and does not make any doughnuts ( circles with holes in the middle where the epoxy did not stick to the wood ). The reason I am asking that is when ever someone has anything oily around the wood and it gets on it the epoxy will not stick to it. That includes sprays or just oil off the hands from handling a can of WD-40 and stuff like it , will do it.
What has me worried is you used an oil base paint and the questions is , how much of the oil was saturated into the wood , if any.

This is a special concern when doing the glassing and the wood is going to show , by doing the bottom with the graphite no one will see them and the glass would be over them with more epoxy on it. A few small ones should not be a problem , if there are any at all.

I may be putting the cart in front of the horse but it is something to think about and could happen. With any luck it won't.

 

[Oyster]

I will explain the reasoning for my alternative recommendation.

Finishing cloth which is what most are suggesting is not tough at all, especially the 3 oz stuff. the way that I read your post is that you have dragged and scratched the finish off and allowed wood to check out. You need to take to bare wood for sure and countersink any hardware and fill with thickened epoxy. There is some of the 20 oz around if you want to go that way but rarely gains any real strength, something that is not part of the issue here that I see. Your most important part of the redo is to create the barrier coat over the glass.

I can attest to you that three coats of the Interprotect over the glass after filling the weave is one tough layer of resistance to sand and pebbles. The reason I use this is that its a uniform mix and can be recoated without the bull work of any real sanding up to over two weeks. The material is basically a thin layer of aluminum too and in the case of redo much easier to fix and clean up opposed to the graphite.

Logs normally spread across a larger area of the bottom so unless you hit them head on the issue of impact and rupture is really not an issue. With enough weight inside the boat and an impact on the edge of a log, nothing will stop the penetration short of a layer of kevlar if you are going any speed in most cases, IMO.
If you are asking about costs consideration, thats really mute considering that you hope to do this one time and only consider a clean up later without have some hidden fracture of the glass and water intrusion recognizing this also too late. my pennies worth and you can keep the change.

 

[tx river rat]

Ok here goes an opion and some questions
Everything I ever recieved from the little schooling I had on fiberglass layup said you dont hit maximuim strength until
all the glass is covered and a smooth coat on top.
The question is this if you do not completely fill the glass cloth and then apply epoxy with graphit what happens when you go to refinish,graphite and epoxy will be down in the low spots in your cloth,do you sand down into the cloth before you refinish
.I would assume after the epoxy graphite is cured another coat doesnt addhere to well.
Ron

 

[Kayak Jack]

Ronnie,

My experience is that the first coat of epoxy on glass should be clear. After that you can have it clear or fortified with the powdered graphite. RAKA recommended about 20% graphite by volume. That worked nicely for me.

When I resanded, I stopped short of the glass. Being inherently a bit lazy, I stopped when I had sanded down to either the dull gray, or smoothed edges on any gouges. In other words, don't sand any more than you have to.

 

[gbinga]

Here are a couple of thoughts;

-You said the boat is strong enough, and that what you want to accomplish is to stop the checking of the wood.

-The checking of the wood is characteristic of the wood. You used marine fir, if I remember right. It gets cracks and peeled places just like BC pine does, right? So it doesn't really have anything to do with abrasion or damage, it is the wood checking with exposure to moisture.

-Of course abrasion resistance is a good thing - - everybody runs into snags and rocks and such.

I wonder if anyone has ever tried using builders paper or rosin paper (buy rolls of it dirt cheap at the building supply) to surface a piece of plywood and keep it from checking? What I envision is;

-Saturate the wood, let that cure.
-Roll on a second coat of epoxy, let it cure until it is tacky.
-Roll on a layer of heavy paper onto the tacky half cured epoxy. Get it down nice and smooth. Let it cure to the point where it isn't coming loose.
-Put additional coats of epoxy on top to saturate the paper and use additives for abrasion resistance if you feel like you need to.

I realize this ain't conventional or proven. The reason I'm suggesting it is that Joey isn't looking for strength, and he didn't originally say anything about abrasion resistance. He is trying to control checking. This method would be cheaper, and I bet it would be lighter than glass. Glass takes quite a bit of epoxy to wet out and top coat to the point where it is ready for finish. More epoxy means more dollars and more weight.

This is something I've thought about doing before to control checking on plywood. I have not tried it, and have not heard of anyone trying it. Just an idea. Maybe I should try it on a piece of scrap wood and through it out in the yard to see what happens.

BY THE WAY-- has anyone ever had problems with graphite on the bottom getting too hot in the sun when the boat is sitting upside down on top of your truck or out in the yard? Black finish out in the southern sun ought to get HOT. And epoxy can only take just so much heat before it softens. I reckon one of ya'll would have seen it happen if it was going to happen, but it makes me curious.

George

 

[oldsparkey]

George.... Good question , might have to do a scrap piece of wood and find out.

After you do the epoxy and graphite , If you sand it the whole things turns gray since you remove the shinny exterior coat of the epoxy. It actually makes is slicker since that covering coat of epoxy is gone.

Down here in the land of Heat , Humidity and Hurricanes with the boat on the buggy I have not had a problem. If it is winter and there is a frost on it , when the sun come out that frost does vanish. I guess the reason for not having a problem is the boat is only that way from the house to the water and then later back home. Never have left it out in the yard , upside down for an extended time limit to find out.
Has been on the top of the buggy for a day going to a camping and paddling area and I could not see any problems when it was taken off to have some fun. YES , It does get hot , just like anything black or dark does in the sun. I would not want to sit on it since the black seats in the Jeep offer all that enjoyment when in full sunlight , especially when I am wearing shorts which is 51 weeks a year. :roll:

 

[jdupre']

OK, lots of good points and suggestions. George, that paper idea could work. I've read that people have backed wooden bows with paper and it stopped the back from raising up a splinter. Paper IS wood, just a homogeneous form of it. Sounds plausible, but I don't want to take that risk on my first foray into fiberglass.

Ron, I never thought about repairing the graphite/epoxy down the road. If sanded, does it allow enough tooth for another layer?

Chuck, I'll try a test on the sanded wood to test for saturation and "doughnuts". I will either paint or graphite the sides and bottom so no one will see any flaws.

Joey