.21 sponson specs

[Ron Zaker Jr]

With Paint.......

cool piece man!

 

[Terry Keeley]

Vac forming ABS would be even easier I'd guess...

wow that's absolutely beautiful! Would like to see more of this type of vacuum-bagged CF fabrication come along for complete construction of outrigger sponsons and hull/tub. I don't see why not? What are you using to create the initial "plug" from? solid block of wood? Also what is the vertical sheet material glued inside sponson? And that's to provide some structural support for boom tube I assume (once drilled through from side)?

Thanks.

Plug is just 5lb Klegecell foam on a G10 base, a little fibreglass and primer to finish. The verticals are again just G10 and are to support the tubes.

Here's one of the tubs I built in '99 from CF braid, same stuff used for bikes and golf clubs, 13 years later and still going strong... ^_^

 

[Terry Keeley]

With Paint.......

Very cool!

Terry, comming from the carbon fiber master, that is a real compliment.

Thanks, Charles

Oh I wouldn't say that, you should see what some of the airplane guys are doing, check this out:

http://www.rcgroups.com/forums/showpost.php?p=14769291&postcount=204

 

[Charles Perdue]

I mostly use balsa for the plug. One of the tricks I use is to make up the plug from 1/4 to 1/2 inch thick balsa planks glued together so as I shape the plug, I have reference lines to help keep it symmetrical.

Terry I remember talking to you and seeing that boat at the first internats in Jackson, TN.

The sponsons on this boat are the last (there were a lot before them) design that I am using. The aero part of the sponson package has a sweet spot of about 14 degrees ( 7 up and 7 down) so that when the angle of attack change of the sponson is made, it only effects the running surface, not changing the lift or down force on the sponsons. Makes them much easier to adjust.

 

[David Bryant]

Plug is just 5lb Klegecell foam on a G10 base, a little fibreglass and primer to finish. The verticals are again just G10 and are to support the tubes.

I see. So you literally build-up foam on a G-10 base, then shape (or machine) to specific dimensions?
Are those the actual sponsons used in the picture (I assume they are)? The Klegecell foam adds structural strength? Can't see from your images, but do you sheet the bottom (riding) surface using plywood?

Also you fabricated a plug for the tub/fuselage? Is it two-piece design (top half and lower-half)?

Thanks!

 

[David Bryant]

I mostly use balsa for the plug. One of the tricks I use is to make up the plug from 1/4 to 1/2 inch thick balsa planks glued together so as I shape the plug, I have reference lines to help keep it symmetrical

interesting. You laminate layers of balsa then shape or machine to specific dimenisons?
How are you finishing or preparing plug once desired shape is achieved? Do you prime or paint?

 

[Charles Perdue]

I make a balsa block to the width, height and length of the plug, then mark all of my reference lines on the block. I have a 6X48 belt sander and rough shape the block a little larger than the marks. I then use a sanding block with 80 grit paper and take it to the final dimensions, then a quick going over with some 320 grit. Seal the plug with west systems epoxy, the next day hit it again with the 320 paper and spray it with lacquer heavy build rattle can primer. Do this a couple of times, then wax with Partall Mold Release, spray with PVA, let it dry and lay up your mold.

Charles

 

[Terry Keeley]

Plug is just 5lb Klegecell foam on a G10 base, a little fibreglass and primer to finish. The verticals are again just G10 and are to support the tubes.

I see. So you literally build-up foam on a G-10 base, then shape (or machine) to specific dimensions?
Are those the actual sponsons used in the picture (I assume they are)? The Klegecell foam adds structural strength? Can't see from your images, but do you sheet the bottom (riding) surface using plywood?

Also you fabricated a plug for the tub/fuselage? Is it two-piece design (top half and lower-half)?

Thanks!

Sorry, giving you conflicting info. The sponsons on my heat boat in the pic are just regular WOF (klegecell), just wanted to show you the tub which is a one piece "braid" over a foam plug.

For the SAW sponsons I made in the mold the plug is Klegecell cut and sanded to shape then glued to the curved G10 base. Bottoms are sheeted with 0.010" G10.

Here's the boat those were made for and the build:

http://gallery.intlw...s.php?album=707

 

[David Bryant]

I make a balsa block to the width, height and length of the plug, then mark all of my reference lines on the block. I have a 6X48 belt sander and rough shape the block a little larger than the marks. I then use a sanding block with 80 grit paper and take it to the final dimensions, then a quick going over with some 320 grit. Seal the plug with west systems epoxy, the next day hit it again with the 320 paper and spray it with lacquer heavy build rattle can primer. Do this a couple of times, then wax with Partall Mold Release, spray with PVA, let it dry and lay up your mold

Ah, I see. Just the kind of detail I was looking for. Thanks

 

[David Bryant]

Sorry, giving you conflicting info. The sponsons on my heat boat in the pic are just regular WOF (klegecell), just wanted to show you the tub which is a one piece "braid" over a foam plug.

okay, I see. Interesting, one piece fuselage lay-up? Beautiful job
Those sponsons are "conventional" construction- ie. shaped Klegecell with plywood sheets?

For the SAW sponsons I made in the mold the plug is Klegecell cut and sanded to shape then glued to the curved G10 base. Bottoms are sheeted with 0.010" G10.

I see. Nice work. Especially fabricating the curved G10 base.

Here's the boat those were made for and the build

very cool. Thanks

 

[Terry Keeley]

Those sponsons are "conventional" construction- ie. shaped Klegecell with plywood sheets?

Yup!

 

[Ron Zaker Jr]

Those sponsons are "conventional" construction- ie. shaped Klegecell with plywood sheets?

Yup!

Plug is just 5lb Klegecell foam on a G10 base, a little fibreglass and primer to finish. The verticals are again just G10 and are to support the tubes.

I see. So you literally build-up foam on a G-10 base, then shape (or machine) to specific dimensions?
Are those the actual sponsons used in the picture (I assume they are)? The Klegecell foam adds structural strength? Can't see from your images, but do you sheet the bottom (riding) surface using plywood?

Also you fabricated a plug for the tub/fuselage? Is it two-piece design (top half and lower-half)?

Thanks!

Sorry, giving you conflicting info. The sponsons on my heat boat in the pic are just regular WOF (klegecell), just wanted to show you the tub which is a one piece "braid" over a foam plug.

For the SAW sponsons I made in the mold the plug is Klegecell cut and sanded to shape then glued to the curved G10 base. Bottoms are sheeted with 0.010" G10.

Here's the boat those were made for and the build:

http://gallery.intlw...s.php?album=707

that long antenna is killing MPH LOLOL.