Wednesday, December 23, 2009

Merry Christmas!

I want to thank all my blog followers a Merry Christmas and a Happy New Year!

/Niklas Edlund

Saturday, December 19, 2009


Updated January 2011: This outrigger is now updated (and the earlier pdf's are removed) - you can find info and pdf drawings of the new the JAE .45G 2011 edition if you click HERE.

Here are the plans for the JAE.45H/G. We have included on the plans both the "H" and "G" sponson designs. Both sponson designs perform exactly the same.The only difference between the sponson designs are their appearance.

The "G" [Geraghty] sponsons are easier to build and the "H" [Hall] sponsons are more retro in appearance.The protoype of this boat has been running for quite some time now and one word sums up the performance of this boat - the JAE.45H/G is a "beast". The boat is brutal fast, turns like all the
other JAE boats and handles some of the roughest water I have ever seen.

Get the turnfin for this boat from David Preusse at The turnfin for this boat is critical.

Updated January 2010:
there is no plans of making the JAE .45HG into a kit through Zippkits etc. Also, the JAE boat plans for the larger displacement motors will require some personal design initiative and hardware research and possible installation modification to fit your specific needs. The larger displacement JAE boat plans were never intended for the novice builder. If these plans are confusing to you, maybe you should consider building the JAE.12G (or JAE .21G2) from Zippkits as a warm-up... The instruction manuals are excellent and the same building techniques can be directly translated to the JAE.45HG...

/Rod Geraghty

Sunday, December 6, 2009

Building sponsons with CA part 2

Here's the second part of the building sponsons with divinycell/Airex and CA glue pics I published a few years ago at the old International Waters gallery.

Missed part 1?

Do note that these build pics are ment to show the principle of building it with CA glue and give you ideas to do it yourself. The actual design of these sponsons are the ones I did in 2006 that are the ones that are included for the first Freebie PDF drawing I published a year ago. Today I would not make them this way personally (see the Freebie .21 V1.09). At that time we thought it was needed with non-trip chamfered cuts etc. But we have now found out they arent needed so the over all width of the sponons can be made narrower = the same as the width of the running surface. The narrower design of the sponsons makes it kind of not needed with the anti-chine cut also but thats up to you.

Some tools I use. I have tested ZAP green and Great Planes Pro CA medium together with GP pro kicker. It works great with Divinycell H60 & H80 (and Airex C70.55/C70.75). If building bigger sponsons then 21 size maybe you should use a slow setting one though - or if you work sloooowly... ;-)

The outside angled chine-cut is made - glue the plywood in place. I used 1 mm plywood here. Trim it down after it has set. I would recommend only to final trim its edges down WHEN your done... If you trim the plywood edges down after each step all the time, you're very likely to sand through the plywood as you will affectively sand the same spot several times... Only sand down the edges that you need to do for the step you will do "now" if you know what I mean. If, not - think about it for a while and it will sink in... ;)

2 mm thick lite-plywood is used for the top (3-ply version). I have used 3 mm also, one can have the top edges even smoother and even more radius then... (Updated: use normal 1.5 mm airplane birch plywood instead - it will be lighter and stiffer!)

The rear step plywood strip is glued in place. The one to the right is trimmed down to the same angle as the foam (2.5 deg). Also the rear step is sanded down to the same angle as the sponson ride surface = 2.5 deg - that is of course done before the plywood strip is glued in place...

Trim the 0.8 mm plywood down to the same level as the bottom. Leave the sides a little wide...

Here the lite-plywood is trimmed down. But as mentioned here above use normal 1.5 mm airplane birch plywood for the top instead. It's lighter and makes the sponsons more rigid.

The rear step bottom skin is glued on - 0.8 mm plywood is used.

Trim and guide lines.

Trim lines shown. The one on the foam is a glue guide at this point though for the bottom skin. The side line is parallel to the ride surface. The two lines meet at the front...

The bottom skin is glued in place supported with the cut away foam. 0.8 mm plywood is used.

Ready to be skinned with plywood.

For that final good "fit", when almost ready with the sanding, use light pressure on your bar sander so the foam and plywood are sanded perfectly level - then there wont be much of an visible air gap... if any.

The chamfered outer plywood is glued in place (1.2 mm) and trimmed.

The leading- and trailing edges band-sawed away and sanded smooth. I use 10x10 mm hardwood for the rear tip and 10x15 mm for the front.

20 mm wide 1.5 mm thick riding surface plywood glued in place - they're 130 mm long. Front and rear hardwood blocks glued in place (with CA).

When CA gluing hardwood - one needs to hold the parts in place way longer... Don't use kicker to begin with either - press together for a couple of minutes and then use kicker (updated: you could actually use a little "dust coat" of kicker on the wood). Then the glue has time to soak in the hard wood better.

They're almost done. Will drill the holes for the 8 mm carbon tube rods later plus also the 6 mm holes for the fin mounts.

The final sponson. Its just sanded "roughly" smooth - the final sanding will be done just before epoxy prepping and paint.

The trailing edge of the bottom is sanded at an angle to the front.

Close up.

Sanded smooth to blend in with the bottom... Keep the edges sharp!

Close up on trailing edge.

Leave all bottom riding surface edges sharp!

Front part sanded somewhat smooth. The 20 mm wide bottom plywood chamfered smooth so it blends in with the bottom.

Front hardwood nose piece sanded smooth. I like my leading edges to have big radius...

The rear trailing edge sanded smooth, first in a table top band sander, then by hand with GP bar sanders.

Side chine-cut sanded somewhat smooth. This is the final uploaded picture for now... The left sponson at this point weights 64 g and the right weights 70 g. The right hand one uses a thicker inside... Its not super light for sure - I just wanted to test how heavy a pair would be - I cant build them heavier then this... ;)

Monday, November 30, 2009

Kep's .21 Freebie V1.09

Update (October 2012):  I'm happy to announce that Friday November 2 2012 I will publish a completely new PDF template freebie design - the KEP's T2 .21. So welcome back soon and download the next generation racing outrigger hydroplane freebie! Read the T2 presentation HERE.

UPDATE MAY 2010: The pdf's to this earlier "old" freebie is removed. I have uploaded new drawings for an up to date RACE2010 version of it. Click HERE.

I have updated the original Kep's .21 Freebie PDF drawings to V1.09. The tub is the same as the earlier one so that template is not updated.

- Front sponsons are updated with slightly more built in AoA on the running surfaces. The running surfaces now have no "V" angle either = completely flat if you look from the front (or back). They are also simplified so there are no chine angles and no non-trips either so the complete sponsons are narrower. Its also updated with running surfaces overhangs to the sides of the sponsons. The C-C of the sponson tubes are exactly the same as before.

- The turn-fin location in the sponsons is moved to the front = better handling.

- New turn fin design includes multiple mounting holes.

- New rear sponsons with no non-trip angles - easier to build.

Here's a link to the original and first version of the Kep's .21 Freebie PDF drawings.

Save the pdf's on your favorite movable storage media (such as an USB stick) and go (or send by e-mail) to your local print shop and have them print them at 1:1 size or 100% and they should come out at the right size.

This is the main V1.09 updated pdf drawing including the "old" tub etc. The templates are at the bottom which you just cut off and make templates out of.

If you already have printed out the first version of the PDF main drawings or you may already have built a Kep's .21 Freebie tub - then you only need to have this file printed. It contains the front and rear sponson template profiles and the new turn fin design (all 3 are the same - you may want to make some spare ones!?).

If you only want to make some new turn fins this is a file with only that and a template for a stiffening brace plate. It fits the first version of the Kep's .21 Freebie also.

Have fun building!


Building sponsons with CA part 1

Here's another set of pics and some info that I published a few years back in the gallery section of International Waters forum. The original link is to the right marked as "Kep's 21 build tips #2" or you could just klick here.

As mentioned the pics and texts where done a few years back. The actual design of the sponsons in the pics is pretty similar to the ones in the original Kep's Freebie PDF drawings.

Today I would not build them exactly like this with chine-angles and non-trip angles etc but I hope you find the info and pics somewhat inspiring at least!?

Building is fun! :)

Also read my earlier blog about the glue test.

Couldn't live without them, Great Planes bar sanders - I use almost exclusively 80 grit paper.

Sponson templates made from 1.5 mm plywood. The drawing is glued on with spray cement. Be very careful when cutting them out. Cut them on the inside of the outline. I make my boat drawings in Illustrator.

Template with 1 mm holes for making a punch hole to the plywood sponson insides.

A set of inside parts for 4 pairs of sponsons. Its way easier and faster to do more then one set at a time. The plywood is hold together with pieces of carpet tape.

Divinycell H60 closed cell PVC foam core material. In this case for building a pair of .21 size sponsons. Works very well with normal CA glue if "right" technique is used. When I have tested - CA glue makes a superior glue joint when skinned with plywood vs epoxy glue - on Divinycell H series that is...

4 left and 4 right inside plywood parts after they are "broken" apart. R = 2.5 mm & L = 1.5 mm.

2.5 & 1.5 mm thick.

Another view of the plywood insides. Ready to be CA glued to the foam core.

Use the inside sponson template and make a rough outline on the Divinycell foam. Vacuum the foam or blow the excessive dust away... Spray kicker on the plywood, then spread CA glue on the drawn line all the way around, then fill it in in a zig-zag "pattern" between the lines. Apply the "pre-kicked" plywood (kicker side down!) to the Divinycell. Then turn it upside down and push down. It helps if you have a flat surface of course and some plastic wrap or similar so you wont glue you sponsons to the table...

The CA glue has set.

Maybe I have used too much CA glue... Speaking of glue - I have only tested Great Planes Pro CA medium and slow + ZAP green + slow. They all work the same - no difference what I have seen. The slow/thicker one just isn't needed for how I work. If you're slow working or uncertain how well you will do, try out the slow curing ones. Make sure to add kicker to the plywood part (no glue added there).

After cutting the upper part away in the band saw, use the bar sander to smooth the top surface. Not important at this stage to make it perfect. Use the top view template and make a line for the outside cut.

Before you take it to the band saw again. Sand the outside and keep it at 90 degree measured from the bottom that is 90 degrees from the inside... Right!? When working in the band saw, check that it saws in 90 deg (adjust the baseboard of the saw). Pay attention to making the band saw cut as close as possible to he line and be smooth. The outside back-support wont need any sanding - it will support the ply good anyways...

I make an simple matching line with a pen on the foam. Its way easier to make it right as one doesn't have sooo much time as with epoxy...

After the band saw. Only 2 of these parts is used. The outside and bottom parts are used for support when gluing those plywood parts to the foam core.

The outside is here ready to have its plywood glued in place.

After the band saw. The outside is sanded smooth - the other parts are not sanded yet.

Ready to be glued. The guide line is on the inside of the plywood also - it just makes it easier. Kicker on plywood and CA glue on foam - press it together for about 60 sec. Use a little extra kicker if needed. Use a table fan to remove the glue and kicker odor...! BTW, use some throw-away vinyl protective gloves also.

The CA has set. The cut away foam part is used as back-support. Only hand/body pressure is used. No weights etc.

On this set of sponsons I used 1 mm plywood on the outside. When measured its 1.2 mm though. On the thick side I guess, 0.8 mm isn't a problem.

After the CA glue has set. The plywood isn't trimmed yet...

The top part is sanded smooth and in 90 deg to the inside. This is the guide lines for an chine-cut.

Short depth of field here - oops. The "curved" part here gives itself... Viewed dead on (from the front or back) its completely flat.

Bad picture... Just a view of the angled chine-cut before the plywood is glued. This "version" is perfectly straight and parallel to the inside. One can do them different or not at all... Its all up to you.

Stay tuned for part 2 within a few days...