F.A.Q'S & Hints

[oldsparkey]

WARNING..... Working with epoxy

This was on the ole forum and we lost it. Most of us know it and it is just understood but if you are just starting then you do not know about this.

When working with epoxy and building a boat make darn sure you have a piece of plastic (garbage bag, zip lock bag, Plexiglas 1/8 in will do, or anything that the epoxy will not stick to) under the area you are working on and also above it with a light weight on it to hold down the joints that have to be epoxyed. If you don't then your work will be attached to what ever you have it laying on. Plus the board that you have over the joint that you are epoxying.
Always place a weight on a board over your work and not on the work or seam. The board distrubates the weight.

In this case the less weight is better ... less is better because you don't want to squeeze out all of the epoxy that you want the wood to soak up for a good bond.

EXAMPLE ...... two sheets of 4 by 8 plywood as a work table and you are doing a butt joint on the two side of your new boat. When you go back to check on it you will have the sides glued to the two 4 by 8 sheets of plywood or for better words one 16 foot by 4 foot side board for your boat, when all you needed was two 10 inch by 16 foot side boards.

The smoother the item the less work you will have when the epoxy dries and you have to start sanding the wrinkles out to have the finish on your boat that you want.

I like the strip of Plexiglas 1/8 in thick and about 4 feet long and 12 inches wide. No spill over with it and a lot less sanding , plus my work is not stuck to my work table.

I put this in the pirogue section because most of us are working on pirogues.... Just don't forget it or you will really have a bad day , but a lot of firewood.
Chuck

 

[oldsparkey]

Scary or Butt Joints

Scarf or Butt Joints..... By Kayak Jack ?

Congratulations on taking the plunge. When I built my first boat I was as apprehensive as I was the first time I got married. Both activites got easier with practice; one provides lasting joy.

If you think you want to do a scarf joint, practice with some scrap wood. BUT - do the scarf joint before you measure, mark and cut the wood! It's diffficult to impossible to predict how much length will be eaten up by the scarf joint. It's easy to end up with a long plank that isn't quite as long as you'd hoped it would be.

Like Swampy, I favor the butt joint with reinforcing plates on the inside. I make these reinforcing plates of 1/8" plywood, 2" wide, and as long as the joint. Bevel the edges to about 30 degrees. You can put them on either before or after glassing the inside. I think it's eassier to put them on first.

The true test of a joint is "is it as strong as the parent material?" IE: if I make a joint and then tear it apart, what fails - joint or parent material? Every joint will either add weight, lose strength, or both. A butt joint adds weight AND strength, but - how much can a 2" wide strip of 1/8" plywood weigh? In the grand scheme of things, a butt joint is supremely easy, strong, and reliable.

A well-done scarf joint is an elegant solution that is strong and reliable too - but hellishly difficult to learn to do consistently well. Doing the same scarf joint repetitively allows both practice, and setting up a jig to hold the wood. Otherwise, you have to have had enough practice until the different applications of a scarf joint all begin to appear to your experienced eye as though they are alike. That takes a lot of practice, and a helluva lot of plywood.

Butt joints with reinforcing plates are easy to do the first time, & just as easy on the 10th one.
_________________
Kayak Jack
Doing what you like is FREEDOM
Liking what you do is HAPPINESS

.I spent most of my money on whiskey and women ... and I'm afraid I just wasted the rest.
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Jack likes the wood and I use a 5 inch wide piece of 6oz or heavier glass to cover the whole seam . A piece on each side works really good.

Glassing the joints ......

Pick up some Plexiglas panels to use when the panels are butt jointed together. The Plexiglas will give the seams a lot smoother finish (to the joints) and require less sanding. Plus you can see the seams and make sure they are totally epoxyed and the glass is smooth.

I use the plexglas in place of a piece of plastic with a board over it to hold everything while it cures.

Chuck.

 

[oldsparkey]

Attaching the sides to the bottom of a pirogue

Attaching the sides to the bottom ....

For a multiple paneled boat like the canoe I made (5 panels on each side) you can lightly sand the inside edge of the panels so you have a flush area meeting and not two square edges.
Then lightly stitch with some copper wire and when everything is just right tighten the stitches down and spot epoxy all of the seams.
I call it spot welding with epoxy. After it sets then remover the stitches and filet all of the seams.

If you have any doubt's about your boat being square when you have it stitched and before you glue it. Take two pieces of boards, PVC pipe, anything straight about 6 to 8 feet long and lay one across the forward part of the boat and then do the same across the stern. Now back off and (eye ball it) see if the two straight pieces are parallel to each other and not looking like a kayaker paddling. They should look like this = or this ---- not this >< .

If it looks like someone paddling a kayak that then get a friend to hold one part of the boat while you do an adjustment on it by twisting your portion to make the two bars even. Then tighten everything down.

Now a pirogue has only two seams (sides) to epoxy and I don't follow Uncle Johns recommendations on how to do it when attaching it to the bottom.

I fit the bottom to the sides with a little overlapping each side. Then I attach the bottom to the ribs and end pieces starting at the middle and working to the ends with some screws (which are later remover). Two per rib and 1 in each end piece. Check the shape of the boat.

Then I turn the boat over and secure the bottom and any gaps with straps or duct tape all the way around the boat to pull it together.
If you use straps then make sure you have the strap covered with a cut zip lock bag between the strap and the boat at the seams or the strap could become a part of the boat.
When everything looks just right I spot weld the sides to the bottom with some epoxy from a dental syringe. When it cures then everything is removed and the seams are filleted.
I have found this system to be a lot simpler and very easy to do.
Chuck.

 

[oldsparkey]

Rub rails & Spacers ...plus some hints

Rub Rails & Spacers.

I cheat and get the trim molding at Home Depot. It is 1/4 inch by 1 inch or up from there. It can be purchased in the total length of the boat ( 16 foot or longer pieces) so it does not need to be spliced together. It is usually knot free and does not cost that much.

The outer one is just epoxyed on the boat while the inside rail has spacers behind it (between it and the inside of the boat) this gives a person a lot of places to use as tie downs for gear inside the boat or to tie a net over the gear. The spacers are nothing more then the same molding cut into 2 to 3 inch pieces and spaced the same distance apart on the inside so the inside railing is then epoxyed to them.

Helpful Construction Hints

When I make a pirogue I fasten the bow, stern pieces and ribs to the boat with screws. Make sure you drill a small pilot hole 1st , to keep the wood from splitting.

Then when it is together, I remove the screws and epoxy the pieces then reattach them with the screws. When the epoxy is dry the screws can be removed or removed later before glassing the boat. Just fill the holes with a wood flour and epoxy mix then sand it smooth.

Also before picking the boat up make sure the outer rub rail is attached to the boat or you stand a chance of breaking one of the ribs since the sides of the boat want to bow out when it is picked up and nothing is supporting the upper sides of it.

Chuck.

 

[oldsparkey]

The Graphite & Epoxy mix for the boat bottom.

When the boat is done and you want to protect the bottom there is a trick that I do for my boats and it does offer a lot of protection.

Use some epoxy and graphite powder to coat the bottom and a couple of inches up each side of the boat.

Tape off the sides where you want it and then mix up some epoxy and add the graphite powder then roll it out on the bottom. Three coats, three days apart will do the job very nicely. Make the coats light and they will build up. The 1st coat you will still see some of the wood, the 2nd coat should cover it so very little or no wood shows thru then the 3rd coat is the final one. Let it cure two weeks and it will protect the bottom from scratches and a hidden benefit is it also makes the bottom of the boat slippery and easier to paddle through weeds or over logs.

To mix this you need to use a container that this can be mixed in and it is messy so wear gloves.
Add some of the (resin) epoxy (NOT HARDENER) to the cup, now add about three or 4 spoons of the graphite powder (add graphite of about 20% of the mixture by volume) and stir it really well so no lumps are there. Stir it again just to make sure it is mixed.
NOW add the HARDENER and stir it again .... At this stage I pour it in a paint tray and get the roller and roll it out on the boat. Let it dry overnight and then repeat the process.

Just make sure this is the LAST thing you do to the boat because nothing will stick to this mix.

Chuck.

 

[oldsparkey]

Applying the epoxy....with rollers

I get the short nap 9 inch rollers for epoxy and cut them in half .... Gives me two 4 1/2 rollers to use. The rollers are also for enamel but on the wrapper it will also say for epoxy.

Home Depot sells them and they are from (linzer) One Coat Paints , 3/16 nap for all paints Smooth Surfaces ...urethanes , epoxies & enamels ... they are non shed fabric. In a partial black wrap with a blue line.

They are all I use for applying the epoxy both to the boat to saturate it and later for putting down and coating the glass. You might waste some epoxy in the nap of the roller but not near as much as using the squeegee.

With the roller you will get the glass to lay down and it will not move as much as with the squeegee or a foam brush , plus the roller is a lot quicker and easier to use.
Chuck.
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[oldsparkey]

Trueing your panels & getting the stiching holes correct.

If you are making a multi panel boat here is a easy way to get all of the panels uniform.

Now that the panels are cut out it is time to make sure of there shape. The original paddle for each section was cut just outside the lines and all the rest were cut outside that line. They are oversize so now I need to get all of them the same size.

Took the 1st stack and put them together on top of each other with the original panel on the top. Squared off the ends and using "C" clamps, clamped all of them together. Checked and double checked the fit and when it was right I took my drill and put in a 5 inch sanding disk. Ran the drill and disk along the top & bottom of the panels till all of them were sanded flush with the top panel.

This just makes sure all of them are the same size and shape, you might say uniform in all manners even mistakes if any have been made.

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Uniform stiching holes.

Then I took a piece of yardstick , (I epoxy coated it to make it last longer, so far this is the 3rd boat I have used it on .. I do not stich the pirogues) that is cut down to 7 inches with two holes drilled at 6 inches apart in the middle at each end of the piece. You place it on the edge and holding it flush with the panels drill thru the 1st hole in it, then the 2nd one. Leaving the drill bit in the hole you just drilled swing the stick around and when it is flush there is the next hole to drill. Just continue this all the way down the panel and all of your stitching holes will be uniform in space and pre drilled. All of them are 1/2 inch in from the sides and 6 inches apart.
Do the two panels at one time that will be stitched together later, for this to work right.

Chuck

 

[Swampy]

Wax paper works great also for underlying panel glue ups.

I use a router with either a "pattern" bit or a "straight" cut bit . 1/2inch is best. ( In case you have another job where curves are used such as template work) Make sure that the bit is secured each time you use it! :roll:

That is why my planed 11 inch hulls came out 10 1/4 inch....... :cry:

swampy

 

[oldsparkey]

Filleting the Seams and Saving on the Epoxy.

I just found out something that is really nice and make one darn good fillet for the seams of the panels on your boat.

I just fillet in the front bulkhead and bow of the Swamp Girl and used some of the Glass Bubbles from Raka to do the job.
They extend the mix of epoxy by 3 if not more. The cost of them is small and the rewards on epoxy saved are great.

I put the epoxy in my container and then added the glass bubbles, mixed, still runny, added more bubbles, mixed, still runny, added more bubbles ....Just about right. Added the hardener, now it is runny ... added some wood flour for color and kept adding the wood flour to get the color I wanted then it was just right. (the bubbles are white so the wood flour adds the color and also helps to thicken it )

Did the fillet in the bow and it is just as smooth as a baby's rear without any sanding.

Conclusion..... The glass bubbles make the fillet really smooth and extend the amount of epoxy that you use by at lease a third, if not more.

At a cost of $3.75 for a Qt of them (4 oz) it saves a lot of money for the epoxy...really stretches it out.
More bang for your buck and it is my understanding it also makes the fillet a lot easier to sand. To say that I will be using them for the fillets from now on is an understatement.
Chuck.

 

[oldsparkey]

You can make your own hatches .... It is quite simple.

Install a bulkhead. Mark the piece you want to cut out. Using a small saw (I use the Bonsai Saw from Chesapeake Light Craft, it is a small version of a key hole saw.

Drill about 4 or 5 ...... 1/16 holes on the line you drew then insert the tip of the saw and cut out that section.
Now on the backside of the newly formed hole epoxy a piece of wood that matches the shape of the hole and let the wood extend into the opening about 1/2 to 3/4 of an inch, forming a lip all the way around the inside of the hole. This will be what the part you cut out will rest against when placed back from where you cut it.

The easy way to get the lip for the hatch is to take the piece you cut out and mark the outside diameter on a piece of wood then remove it and mark inside that line about the 1/2 inch and also outside the original mark by the same amount.

When installing the rim use the center mark to line up with the hole and everything will be correct.

On the lip attach a thin strip of foam rubber which will act as a seal for the hatch. Reinstall the hatch which is the piece you cut out and secure it with some turn buckles. The ones with the screw in the center and you just turn them to lock the piece in. (they can be made from a small piece of wood and just have the screw hole in the center so it will swivel like it should.
Chuck.

 

[deekay]

Scarf joints

Coming late to this topic I may be repeating what has already been said. When I do my kayak hull panel scarf joints I position the panels one above the other in a staggered stack & plane all four panels at the same time. This gives a larger area of planing which makes for a more accurate scarf angle & easier too. The scarfs can be carefully sanded, but use a fine grade & go gently! Hope this is of help.

 

[coogzilla]

Wood powder

Heres what I do. I have a coffee bean grinder. After ripping stock
on the table saw, I scoop it up and put in the coffee grinder. Makes
nice fine powder. Just make sure the wife's out buying more shoes
or sleeping. Then clean the wood dust out or you'll get in trouble.

Hope this helps somebody. Coogs