Darin's UL1 Race Prep

[Darin Jordan]

OK Gang... I've finally gotten around to taking one of my UL1s out of the box.

First thing I did was remove the stickers and fins, and then I tore the entire boat down. That's just how I roll...

What follows details the things I'm doing to prep mine for racing this season.

WARNING: What follows is in NO WAY authorized, endorsed, promoted, or otherwise condoned by AquaCraft or any entities associated with AquaCraft. Doing many of these actions could very well VOID any factory warrantee on this boat, so please be aware of that before proceeding. This thread is simply ME sharing what I'm doing to my UL1 to get it ready for a season of racing. The content provided is solely from me for the purpose of showing one approach to making this boat race-ready. Proceed at your own risk!

I did pressure test the water jacket (blew into the water lines) and it leaks badly right out of the box. I'm not concerned at all, however, because I know that Mike Z is on top of this.

So, with the boat torn down, I put all the parts into Ziplock bags and set them aside. First setp is to reinforce the turn-fin area. I KNOW that this won't be necessary on later boats, as AQ is working on the issue now, but at least this one is rather soft in the turn-fin area and I think it should be reinforced.

These pictures show how I'm approaching this.

[Darin Jordan]

Next I cut out the hole and fabbed a backing plate for the turn-fin sponson... Backing plate is fabbed from two pieces of 3/32 heavy ply (thin laminations and lots of them) laminated together with epoxy.

I'm using nutplates on the backside and have added a third mounting point. The existing pattern picks up to of the holes in a standard Fuller's style bracket, so having the extra mounting point will give me turn-fin mounting options later. I'd like to see the factory bracket pick up this pattern, as I believe it would be a touch stouter and would distribute the loads better...

To locate the holes, I test fit the backing plate, then transfered the factory holes to the wood and drilled them out. I used a Fuller's bracket to locate the third hole. This step is, of course, optional. Just me planning ahead again...

I have also knocked out the original aluminum backing plate so I'll have a better fit to the fiberglass. I was able to knock it loose by partially threading a screw into it then striking the screw sharpy. Epoxy popped right off.. I have a picture of that at home that I'll post later... It may have helped that I used a wide flat Xacto blade on the inside and sharply "rapped" on it with a hammer in an attempt to pop the glue loose... this may have loosened things up. Just be careful and take your time.

[Darin Jordan]

I pressed in some nutplates, then greased and inserted three 4-40 screws to protect the holes while the laminating epoxy dries on the forward side of the backing plate. Once this dries, I'll fit it into the hull by locating it and holding it in place with the same screws, running laminating epoxy down into the area, then tightening the screws to hold it in place while it dries... making sure to grease the screws well.

I'll document those steps as I do them and update this thread at that time.

[Ub Hauled]

Darin, dude...
this is a great "tut"... although I don't own an UL-1 I can appreciate and use the
techniques here elsewhere...

BTW, gotta love Dremel... handy little bugger.

[Darin Jordan]

I will make the pattern available for the backing plate as well... I need to find out what the final shape will be first... I think this one fits perfectly, but I want to get to the finish line before I decide that for sure...

Also, the "leg" on this extends up onto the top of the airtrap, up flush with the inner wall of the hole... Should help transfer the loads better...

Plenty more pics to follow... once I make some more progress...

[Steven Vaccaro]

Thanks for sharing!! Its a big help to people!!

[LuckyDuc]

Thanks! Looking forward to the template. If you get a chance, can you take a pic of the inside of the turn fin sponson area?

[Flying Scotsman]

No disrespect to Darin, but the photos I have seen seem to point out that the edge of the sponson is the problem...too much lateral force to that area. Should the sponson outside area be fortified also?
PS Grim's response would be appreciated, and I am NOT stating this is a bad model, to the contrary I just purchased one from OSE

Douggie

[Darin Jordan]

No disrespect to Darin, but the photos I have seen seem to point out that the edge of the sponson is the problem...too much lateral force to that area. Should the sponson outside area be fortified also?
PS Grim's response would be appreciated

Douggie

Douggie... I don't know what has previously been shown, but I know what I'm doing... There shouldn't be any force on the "outside of the sponson" once I'm finished with this update. All the load will be transfered to this backing plate and distributed across the airtrap and up to the tunnel area... I can see what you might be saying, however... The pressure from the outside of the mounting bracket, it basically pivoting on the two mounting screws, could cause it to stress the glass along that edge... That won't be an issue when I'm done...

Also... on final installation... There will be plenty of additional "reinforcing when the area is flooded with epoxy to seal this piece in... The main concern, however, is from the mounting screws of the turn fin toward center... That will be the side loading the fin... AND, this backing plate extends the full width of the sponson, so it'll contact that area anyhow...

I've got it covered... at least for my boat... More pics to come shortly...

[Flying Scotsman]

Darin has offered some of the best updates to Aquacraft models and his knowledge, enthusiasm and efforts to support FE boating are second to none. I may disagree from time to time...surprise!! but on the whole Darin and many other DUDES you know only try to grow the hobby with their knowledge. Learn and do not think about suing a manufacturer for a minor problem, as they will be out of business and the rest of us will suffer for your minor $ gain.

Douggie

[Doug Smock]

Darin, good thread sir!!!

Doug

[LuckyDuc]

Darin,

If one was to cut a larger hole in the tub, is there enough room to lay additional glass on the back, sides, top, and bottom of the sponson along with a larger back plate?

[Darin Jordan]

I have the new backing plate in a drying now... Here's what I did...

First, here I've added a picture showing how I located the holes. Basically, test fit the piece, and once you are happy with how it fits, transfer the holes, take the piece out, and drill it up.

With the backing plate out, I used a flat Xacto blade to chissle out the old epoxy as best I could so the new plate would fit as tightly as possible to the surface of the sponson material... It won't be perfect, but it'll get filled with epoxy anyhow, so I just wanted it as close as possible...

[Darin Jordan]

At this point, I'm ready to glue the backing plate in permenantly. I ran a 4-40 tap through all the nutplates to make sure they were clean.

Then, I coated some temporary 4-40 screws with grease, and CAREFULLY filled the holes in the nutplates with grease, to protect the threads from the epoxy. I cleaned up the any excess with laquer thinner...

With all this setup, I mixed about 7.5cc of epoxy for the first pour. I coated the aft side of the plate and all edges liberally with epoxy, then slid the piece in place and threaded in the fasters loosely.

Once the plate is positioned correctly, I snugged down the fasteners as far as I dare without cracking the glass... I was able to get them seated down pretty well, except for the third one I added, but even it's not too bad...

[Darin Jordan]

With everything snugged down, I poured in the remaining epoxy, concentrating on the aft side of the plate. My intent is to fill all the voids and basically flood the area with epoxy, sealing the wood plate in there nicely and filling any gaps between the plate and the sponson transon inner surface. This way the outter glass won't crack when torque is applied do to the glass compressing into any gaps...

I propped the boat up at an angle the would allow the epoxy to stay in the area of concern and turned on the heater and I'll let that cure for 24-hours.

Tomorrow, I'll pour in some more epoxy and repeat that as needed until I'm satisfied that the area is secure and solid.