Darin's UL1 Race Prep

[Darin Jordan]

Blueprinting the Ride-Pads

OK Gang... I decided last night to make another modification to the hull...

I started out by block sanding the ride-pads, but decided that I could get it flatter, and make the surface more durable, with less sanding and filling, by installing some new ride-pads from a harder material.

Here's what I did:

First, I block sanded both sponsons and wiped them down with Mineral Spirits on a clean shop towel.

Next, I cut out two pieces of .031" G10 material, approximately 7.5" x 1.9".

I trued the edges with my belt sander, then fitted them to the existing ride-pad surfaces. I left about .100" overhang at the aft end, and beveled the underside of the new pad slightly so it would fit right up against the anti-submarine pads in the front.

The inside edges are perfectly flush with the inside of the sponson. The outsides overhang just slightly, which will be fine.

[Darin Jordan]

Once they were fitted, I roughed them up a tad with some 320-grit sandpaper, wiped it all down, then put a thin coat of epoxy on both the existing pad surface and the bottom of the new pad.

Taped it in place, clamped things down, wiped off the excess (come back a couple of times to do this as it will continue to squeeze out) and set the assembly up to dry...

Please be VERY careful if you use clamps as I've shown in the picture... the deck will crack if you put much pressure on them. I only used them to help hold some force downward...

Remove the tape and cleanup and you are done... Nice sharp edges, very hard, dense surface, and FLAT... Should optimize the performance of this already fast hull, as well as make the ride-pads much more durable. That's important when you are racing, because inevitably, you WILL flip, and every now and then, someone will run you over... and the sponsons are usually the first thing to get hit!

[Darin Jordan]

Here's what it should look like when the pads are finished... I'll take a few more angles of it tonight when I get home from work...

We'll have to see how this works. My main concern at this point would be the fact that I've basically reduced the step between the anti-submarine pads in the front and the ride-pad surface by .030"... Hopefully that won't cause any issues...

[LuckyDuc]

Pretty slick looking. Where did you get the G10 sheet?

[Darin Jordan]

Pretty slick looking. Where did you get the G10 sheet?

McMaster Carr... Can't recall what the part number was... There are lots to choose from there...

[Kfoss1]

Darin we need pics of the closing to complete the turn fin repair, Great tutorial by the way

[Darin Jordan]

Here are a few more pictures of what I've done to this point.

Once the epoxy on the ride-pads was dry, I block sand the surfaces with 320-grit paper, then with 400-grit. Move lengthwise down the pad. Lightly sand the edges. Clean up, and this portion should be completed.

[Darin Jordan]

Turn Fin Bracket

Here is a little modification I've done to make use of the extra mounting point in the turn fin mount.

I carefully sanded off the black coating from the mounting surface on the turn fin bracket, then epoxied it to a piece of Carbon fiber, drilled up with the correct bolt pattern (standard Fuller's style strut bracket hole pattern works perfectly)...

Once the epoxy sets, I shaped it to fit and I now have a 3-point bracket. When mounted, it spreads the load better. Additionally, should I need to align the fin better, I can use this material as a shim, carefully sanding it at the angle needed to get better turn-fin alignment if needed.

[Capt. Crash]

Very nice thread Darin

This is a very helpful thread....and I sorta wish my pond was hard so I could have done all these upgrades to my boat before I ran it...but the water is soft and I want to play so I will try some quick fixes first.

I am thinking about drilling another drain plug hole on each side of the tub to allow me to squirt some epoxy into the (fractured and unfractured) channel (see oh...oh...post.) I'll have to think on it some more. I added a kick plate to my modified turn fin area. Am I allowed to link to another site on here...if so here it is rather than reposting everything. If not the mod can remove it.

http://www.rcgroups.com/forums/showthread.php?t=965826&page=12#post11415903

Oh...I know the dedicated hard core racer doesn't use shear pins or break away rudders/fins, but I am not doing serious racing and have a minefield of Alligator Snapping Turtles in my pond. I think I already hit one cause my turn fin had a flattened knife edge and may be the cause of the cracked sponson under the turn fin.

Any way...I don't want to hijack the thread so rock on dude!

Oh...I've been meaning to add...the vertical fins don't fit real well or stay on, the way they come, without the outside (hatch) tape but after I sanded a little off the bottoms for a better fit and added some balsa inside for additional flotation, I find a doubled thickness of two sided tape works well enough that you don't need the outside pieces of tape, on top the hatch, to hold them in place.

[Darin Jordan]

Darin we need pics of the closing to complete the turn fin repair, Great tutorial by the way

I haven't gotten that far yet... I'm thinking of actually making it into a removable access panel that screws down, but we'll see...

I'm about done with the upgrades to this point, and getting ready to do some painting. There is likely more that can be done, like maybe what Mike Martin suggested in filling it with expanding foam, but I think I'll pause for now and see how it works at this point.

I'll post more as I get it complete. Hopefully this thread helped someone out there...

[Flying Scotsman]

Darin, I like the 3 point bracket.
Thanks

Douggie

[LuckyDuc]

I was contemplating how to deal with the hole I intend to cut in the tub. I think I might use a piece of clear lexan and silicone adhesive to cover it up. If I do need access in the future I can just pry it off.

[Darin Jordan]

I was contemplating how to deal with the hole I intend to cut in the tub. I think I might use a piece of clear lexan and silicone adhesive to cover it up. If I do need access in the future I can just pry it off.

Yah... that would work... I'm half tempted to just leave it there and open... ALL of my other hydros are completely open in there... if it stays dry (all of mine do), then it's not an issue...

.... until you accidently drop a screw or something in there and can't get it back out, and have to listen to it rattle around...

... I think I'll make a closeout panel for it!

[Darin Jordan]

Did a little more work. Almost ready to wrap it up for now.

[Darin Jordan]

After sanding the areas for painting with 320-grit, then 400 grit, I wiped it all down with cleaner, primed, and I've just about wrapped up the painting. Waiting for some decals to arrive, then I'll clearcoat and be done.

WARNING: I don't know what it is, but it took about 4-coats of primer, and several coats of the white paint, before the red stopped bleeding through... Kind of like on the ProBoat hull I did awhile back. Not sure what happens, but it just keeps coming through...

Painted the center white because I usually use electrical tape to tape the hatch, and this will allow me to use white tape without having it show much... Not an exact white match here, but I was just using up some paint I already had.