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Around my area so far I have been looking around for Wood for my keel. The most affordable option so far looks like 3/4 " sanded fir plywood,  I have found 3/4" hardwood plywood but don't know if that would be any better..  My other choices that I have found so far are Red Oak but at $7.44 a lf that is too pricey. Also poplar $4.52 lf, still expensive. or a wood lowes is calling Whitewood.  Any sugestions?

Living in the South, we have adapted to a few local woods that would fit the bill.  I am presently building a Super Skip Jack and used clear, close grained cypress for the keel.  It glues up with no trouble, sands and finishes well and is certainly within budget prices.  Short of that, I miight use clear white oak but that would make the boat a lot heavier. 

http://www.glen-l.com/

Read about plywood and wood choices for boats.  Do a search of the forums for discussion on wood choices. 

It will be well worth your read.  This is a much discussed topic, every few months.

Essentially, you would want as close to quarter sawn lumber as you can find with little tight knots or knot free. Also as straight grain as practical.  Southern Yellow Pine, Cypress both good choices.  Red Oak, no place in boat building,  it is open grain and turns black quickly. Then mold begins to form.  Avoid common yellow pine and poplar.

White oak on the keel is going to help more than hurt. I would avoid red oak. Yellow pine or cypris will work fine, but you are going to have use what you can find and afford. Bud

Go down to the local big box store and dig through the 2x10's and 2x12's of the regular framing lumber, be sure to buy 16' boards. This forces you to buy wood from older, taller trees, which is denser and with some picking through, you can find perfectly clear stock. When you get it home, rip it right down the middle, so it's a 2x6 or 2x5. Now you've just made quarter sawn lumber and cheap too.

This stock can then be used for stringers, braces, supports, etc., plus it can also be sawn to size for your deadwood, though you will be working with pieces that are less tall then the plans call for. Any time you use 1x10's or 1x12's you'll have to use flat sawn lumber. It doesn't matter what species it is, it will cup, warp, split, twist and have all sorts of defects and grain patterns. Using selected pieces of smaller dimension (as I just described), lets you control the warping, cupping etc. and the quality will be much better. Yes, you'll have to use more pieces, but you'll have much less trouble.

What about building the keel using ply wood like I've read many builders doing?

A couple of builders I know have used Marine plywood,  one or two have used Exterior ply with resin impregnated paper on the outside (designed for sign work) and had good success.  Another used Marine Pressure treated ply.  Generally speaking you are going to have some challenges in fastening it to the hull.  Half of the grain is going in the wrong direction (vertical end gran) and doesn't hold screws nearly as well.  If you drill oversized holes, fill them with epoxy and set bolts into the epoxy the joint will be stronger than the wood surrounding it.  But that is a lot of work.  

One builder simply thru bolted the keel this way, long bolts thru the entire hull bottom and the full depth of the keel.  Set them in epoxy and then put a sacrificial strip along the bottom edge.  The strip was 1/2" X 2 1/4" UHMW Poly. They were also attached using screws set into epoxy to hold it.

You have to pull the hull bottom down to fit to the keel.  In the front 1/3 of the boat the use of screws into end grain of plywood will be nearly impossible to make them hold.  Out of sheer necessity it may force you to use long bolts and thru bolt the keel to the bottom and then cut off the excess length.

How well these will hold up in the long run is still the question.  They should be less prone to cuping, warping and moisture gettting into them from just sitting thru the freeze/thaw cycles.

I used a 2x12 piece of spruce, which I later modified to change the shape of the keel, not because the spruce didn't work just fine, it has.  No laminating pieces together and cost around $20.00, but you have to be able to think for yourself deviating from the plans, so be careful.

(01-19-2010, 08:51 AM)Barry Pyeatt link Wrote: [ -> ]Generally speaking you are going to have some challenges in fastening it to the hull.  Half of the grain is going in the wrong direction (vertical end gran) and doesn't hold screws nearly as well.  If you drill oversized holes, fill them with epoxy and set bolts into the epoxy the joint will be stronger than the wood surrounding it.  But that is a lot of work.  

I had no problems attaching my plywood keel to my Weekender using regular 2" screws and they've held through rollovers (suspending the entire boat upside down by the keel), building dolly failures and a couple of groundings during my one and only launch.  I've had the boat stored outside in Ontario for 3 1/2 winters and everything has held together well.

For glueing the keel I used PL Premium construction adhesive to both laminate the pieces (which I nailed together - not screwed) and to glue the keel onto the boat.  This sort of adhesive has the advantage for me that it expands as it cures making up for less than perfect carpentry.  One thing that I did that I would strongly suggest for any plywood keel though is I put a strip of steel along the bottom of it bedded in roofing repair cement.  This protects the open grain of the plywood from the inevitable impacts it will have.  I also fiberglassed it which is considered a bad idea but plywood is more dimensionally stable than regular lumber and I wanted to protect it from cracking/checking which plywood tends to do.

Andrew,  How did the PL premium adhesive work for you?  I think that is the glue I am going to use. I know it is waterproof and it seals gaps up to 3/8".  I can get it around here for about $49 a case..  One question though, can you sand it?