My XS ModCat LSO build - my first real RC Boat

[Harusee]

Here are a couple of pics of the pieces of the LSO hull layed out so far.

I still have a ton of sponson work to do to get them finished and I am working on a fiberglass bubble canopy form (which I layed in it's approximate position in the pic you can see its not fully sanded and formed yet) which is a lot more work than I thought sanding foam would be. What a Mess!

Anyway, I think its going to come out alright once I get the foam cuts cleaned up. Once I am done cutting foam, I am going to putty all the bad cutting and sand it smooth and put the skins and fiberglass over it. It should be decent by the time I am done. I am thinking about rounding the tops of the sponsons for looks but I may leave it be until I have gotten the first one wet! It measures about 26" long so just a hair over the requirement for LSO. Its about 10.25" wide at the sponsons widest point. Looks mighty stable anyway.

Jay,
Some of the plan and instructions have pics that are too dark to make out. It looks like the ride pad shape is on the plans and that these are attached to the sponson bottoms but with an angled attachment to make them flat. I have a concern about my sponson length since it is an inch longer than stock. Should I adjust the ride pads accordingly? I will not be ready to fiber glass them for another week or two easy.

I cannot wait to get this thing on the water!

[jevmax]

Ray,

That looks great to me! You'll have a ton of fun with that cat and be hard to catch. Bring it to the HOTMBC year-end gathering on 12/9. I'll be running a mono in LSO, but cats are faster. :yeah:

[Jay Turner]

The ride pads have a slight deadrise to them, about 1 to 2 degrees. You can keep them the same length as on the plans, an extra inch or so sponson length at the bow will not matter.

I found the easiest way to shape the foam on the sponons is to use "drywall screen", an abrassive-embedded screen that you attach to a sanding block. It doesn't load up like sand paper and gives a surface smooth enough for gluing on plywood. And yes, the foam dust is a pain! :mad2:


m

[Harusee]

I am a little light on nautical terminology. What is Deadrise?

[Jay Turner]

The angle of the bottom of the sponsons/pads relative to the water surface. With the boat flat on a table, a two degree deadrise means that the outside edge of the pad is slightly higher than the inside edge; the bottom surface makes an angle of two degrees with the table. :yeah:


m

[Harusee]

How fine is the drywall sander for shaping? Sandpaper takes forever and does load up rather quickly but fairly coarse paper makes pretty good shaping passes on the foam.
Does the drywall version take small or large amounts of foam with it?
Does it hang on rough foam or cut it off smooth?

To be honest I have been thinking about getting a whittling knife with a real long, thin, and sharp blade to sculpt the foam and reduce the tiny particulate that invades and sticks to everything when you sand foam. The foam dust seems to be electrically charged and sticks to everything!

[Jay Turner]

The drywall screen does not load up, it cuts smoothly with virtually no tearing of the foam. Try it. It is not for gross shaping, use either 60 grit paper, a knife, or my favorite - a band saw. :yeah:


8

[Harusee]

To be honest Jay I wasn't sure about the dry wall screen but after using it I can say that a better foam shaping and surfacing method besides a nice hot wire set up, I can not imagine. The way this works I should be well on my way. I already layed the fiberglass on the bubble cockpit because the drywall screen actually shapes quite nicely. Except for the dust and mess of the foam I cannot imagine an easier way to work with the stuff! THANKS!

The pics below show the foam glassed up. You can see brown stains in it. That is filler I used to take care of gross imperfections. I will sand the rest out of the glass. I hope it turns out as pretty as what I see in my mind.