Thursday, May 22, 2014

Glider build #2

A long time ago I got my hands on the last and final pieces of some balsa sticks a former balsa blank maker had stashed in his garage.  I think I paid around $500 for everything pictured including the foam.  Not positive.  From this wood there were some 12' pieces and I made my first glider which will be featured later in this post.  This is a short story about glider #2.  

I am laying out the wood to find the best pieces that will get me two blanks.  One is a blank for a balsa pig and the other a really big glider aka...Glider #2

At the time I didn't have a good jointer so I am at my friends shop flattening out some slicks.  

As with most balsa it comes with character.  This piece had great rocker and length but not thick enough.  Here I am gluing on a piece to get it fat enough.  

I am laying out the rocker template on the sticks

Blank on the left is Glider #2 and Glider number one is obvious



Here the board is about 80% shaped.  When I put the blank together I placed a pea sized drop of Elmer's Glue ever 2'.  Ideally this will hold the blank together while I rough shape the board.  However this didn't work due to significant bowing of the wood from L-R.  To solve this issue I drilled a hole in the wood from L-R and placed long pieces of cut All-Thread rods and used large fender washers to pull the boards tight.

Here the board is broken apart and the All-Thread can be seen

This and the next shot are worth a million words.  Here the individual pieces are chambered.  This piece is over 3'' wide so I come in from the L and chamber only 1.5'' and then the R 1.5'' staggering my vertical posts from L and R.  So, on the L side the posts are 12'' apart and the R side 12'' apart but together the posts are only 6'' apart.  The reason this is done 12'' gaps all the way across the board that a knee to bust through.

Notice the offset chamber posts.

Now to make the chambers I turn the individual piece of balsa on the side.  I use a router with a guide touching to deck or bottom of the board.  My deck and bottom thickness after chamber are about 1/2''.  This can vary with the rider and glassing preferences.

This is a great video the Gene Cooper put together on how to chamber.  I do something similar.

Here I am gluing the board back together after the chambering is completed.  It is a must to use the 2x4 battens.  This will keep you pieces of wood from being damaged by the clamps but more importantly they will go back together straight.  Yes, you board could be put together crooked.

I am using old bike inner tubes to clamp the outside pieces together.  The rubber doesn't damage the rails.  

This is a Redwood Burl fin I made for the board.  Roving Halo

Glassing the fin on to the board

Gloss coat.  

Fiberglass Hawaii did a great video on how to glass a balsa board.  Don't take glassing tips from me.  Just do it this way.

Finished at night...shot at night

There is a small pin hole.  This is my vent.  The board will be doing some traveling and I didn't want to risk it.  There are enough stories out there about boards blowing up while flying on a plane due to the altitude pressure changes.  I drilled a small 1/16'' hole that will be filled with a toothpick and glassed over once it reaches it's final destination

Roving leash loop.  Real easy to do.  Take a small piece of 4 or 6 oz cloth and some wet-out roving.  Cut the cloth in a circle and then put the roving in the cloth at about 3'' strips.  Now build your loop and place it face down on your deck lam.  Done...after you drill the hole at the very end.  

Side by side comparison of the two gliders.  Both boards are 12' chambered balsa with the same rocker.  That is where the similarities end.  On the L is a board 25.5'' wide with tons of belly and the fin placed on the tail.  R is a Frye influenced glider.  

At the end of the day Glider #2 weighed 39lbs.  Or about the same weight as the unglassed pre-chambered board.  

Thanks for reading.  Dave

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