"CAT"astrophic day on the lake

[JCAustralia]

Tiqueman

I am using the second motor mount in my Challenger and its great for the price.

The metal plate is watercooled which is a plus.

The orange anodised aluminium does bring a splash of colour. Just watch out that the back end of the motor does not rub against the hatch once installed.

Cheers

JC

[tiqueman]

Heres what Ive been up to in my spare time today. I cleaned the inside yet again. Sanded it some more. I taped off along the edges to prevent a mess around the repair. I then separated the deck from the hull w/ a screw driver stuck in the nose and cleaned the break as best I could. Next I mixed up some 30 min epoxy and applied it into the seam letting it seep through. Then I clamped it all up to dry. (pic 1)

A few hous later I came back and mixed a batch of West Systems Epoxy and added micro balloons to thicken it up a bit. I gloved up and took a brush and gooped it down into the nose of the hull and tried to get along the inner sides of the tips.

After that cured a bit, I decided Id begin to make a bulkhead. After a few 's I finally got a 1/2 template made. I transfered it onto a piece of balsa and tweaked it a bit more to make a better fit. Then I cut a piece of 5.7 CF and mixed another batch of epoxy and laminated one side. (pic 2 & 3)

I had some epoxy left over so I decided to cut a piece of fiberglass cloth (about 2"x 4", soak it in the epoxy, gloved up again and applied it into the nose, placing about 1 inch on the deck and one inch on the hull. I think it worked out pretty well. Tight fit though getting my hand in there. Then I grabbed a paint mixing stick and made sure it was secure in there. (pic 4)

The laminate has dried enough to cut the bulk head close to size. I did a quick test fit and shot a pic. Im going to laminate the other side tomorrow for some added beef. (pic 5)

Im hoping tomorrow to CF the inside of the hull. I will add pool noodles for flotation, glass in the bulkhead, then its getting shelved for a bit. It sucks all this happened, but on the bright side, now Im getting to build the boat the way I wanted it.

[domwilson]

Looks good. Are you going to stay with the same motor?

[tiqueman]

Thanks. Yeah Im going to put the BJ26 motor back in it. I was pretty happy where it was at. I dont want or need that hull any faster. Fifty would have been nice, but it was close enough. I will probably go back to 4S, only running 5S occasionally, to show a friend or something. BUT, I want to make sure whatever new ESC I get for it has the capabilities of running 5S w/ out a problem. Cause I say now 4S is fine. But I have a feeling after I run it on 4S again, Im gunna want to go back to 5 real quick....

[domwilson]

I wish you the best in getting this fixed. I know it's frustrating right now to not be able to run it. But once it's complete, you'll have the joy of the work you put into it.

[tiqueman]

I read somewhere a few weeks ago that you should NOT epoxy in a bulkhead, but rather use silicone or caulk to allow for expansion and contraction in the bow. Something about it could cause stress cracks or lines or something on the outside of the hull where the bulkhead touches the inners of the hull allowing the connection to be visible.

I really wanted to use the bulkhead not only for rigidity but also to close off the bow area incase anything like this ever happened again, the contaminated area would ony be in the back 1/2 of the boat. In theory anyway. Im not positive, only speculatig, that if I were to caulk in the bulkhead, Im worried if something happened again and built up pressure, it would blow the bulkhead seal before anything else. BUT.... (sorry, the mind doesnt stop) if its caulked in, an advantage would be if I hit something and break the hull near the front, the bulkhead could somewhat easily be removed for inner repairs of the bow.

Anyone else have any insight on this? This is the first bulkhead Ive ever wanted to install, I just want to be sure I do it the best way..

[JCAustralia]

Looking good Tiqueman

I was also wondering what's the use of a bulkhead? My catamaran does not come with one....... Is it only to make the hull structure more rigid?

If you seal the bulkhead with say silicone then the air trapped in front can act as flotation . Is that correct? What do you guys think?


Cheers

JC

[tiqueman]

Looking good Tiqueman

I was also wondering what's the use of a bulkhead? My catamaran does not come with one....... Is it only to make the hull structure more rigid?

If you seal the bulkhead with say silicone then the air trapped in front can act as flotation . Is that correct? What do you guys think?


Cheers

JC

Thanks JC

Trapped air would act as flotation , BUT, I wouldnt trust it because if you hit, say a turtle, or a floating rock... and smash open the front of the hull and roll it. Your "trapped air flotation just went bye bye. I would still fill it w/ foam.

I do believe bulkheads are more structure than anything else.

And nothing bothers me more on the lake than floating rocks.

Well Im off to continue carboning. I got the transon laid up and the step downs to the bottom of the hull. Now for the big piece...

[tiqueman]

Got the hull layed up. Now just got to wait for it to dry. Still trying to decide what to do about the bulkhead.

[domwilson]

Looking good. Very nicely done.

[tiqueman]

Thanks Dom. I hate to say it, but Im having as much, if not more fun, rebuilding it than I was running it.

Im getting to a stopping point on it, however, now Im thinking, Im giving the entire inside a face lift and am neglecting the outside. Im thinking of a re-paint.... just dont know what yet.

[tiqueman]

I got a bit more done this past weekend. Motor mount tacked in, changed my mind during installation of the radio plate about 100 times, but heres where its at as of now. I kinda did it like it is for looks rather than anything else. All except the ESC will be hidden under the plate. Just to keep it lookin clean. the ESC will either go in front of the motor or on top of the plate in front of the servo. I want it on the plate, however, it may be a pain to install the batts as all the wires and water lines will be in the way. Im changing the steering to a pull pull, again for looks out the back of the boat. Im also doing thru hull pick ups so there are no water lines outside the hull.

I posted a new thread about bulkheads. I need to get that figured out so I can seal that up.

[domwilson]

Wow! That does look clean. Good Job!

[tiqueman]

Thanks Dom. Its getting there. I ordered some seals and tubing from Steven today. Really my only glitch is going to be figuring out how to make the rudder a pull pull system. Ive got to find or make a dual control arm. I think If I cannot find one, Im going to get an aluminum servo control horn, drill it to fit the pivot shaft in the rudder and drill and tap a hole in the side for a set screw. Ive been trying to find an arm online but so far Ive come up w/ nothing....

[domwilson]

Is your rudder in the center? From what I've seen, alot of guys use cable for that type of setup like on tunnel hulls.

[tiqueman]

Yes its centered. Ive got the cable and everything, I just need to find a control arm that goes out both sided of the rudder.

EDIT, I talked to Steven and he said he has nothing available for that rudder. I will probably have to scratch one.

[domwilson]

Maybe you can fabricate one. A shot in the dark, like maybe from an old servo horn?

[tiqueman]

Thanks Dom. Its getting there. I ordered some seals and tubing from Steven today. Really my only glitch is going to be figuring out how to make the rudder a pull pull system. Ive got to find or make a dual control arm. I think If I cannot find one, Im going to get an aluminum servo control horn, drill it to fit the pivot shaft in the rudder and drill and tap a hole in the side for a set screw. Ive been trying to find an arm online but so far Ive come up w/ nothing....

[domwilson]

Yeah, I saw that after I typed. Didn't want to let some good typing go to waste.

[tiqueman]

LOL I do that all the time

[tiqueman]

Im thinking down the road an 8xl Feigao? Im putting an etti 150 in it.

[domwilson]

Maybe some of the guys with outboards might have an idea.

[domwilson]

Found what you're looking for here... http://206.206.85.209/xtdoc/catalogu...e&store=mhzusa

[domwilson]

Im thinking down the road an 8xl Feigao? Im putting an etti 150 in it.

I think that would be great on 4s.

[tiqueman]

Good find on the control horns!

And thats what I was thinking about the 8xl. A 2s pack fits nicely in the sponson. The 3S doesnt quite fit right.

[domwilson]

Plus you want to keep your RPM's in the 27k-32k range.

[Flying Scotsman]

Scott, that is a VERY nice rebuild...congratulations...that cat is 32" long what speed are you looking for, an 8XL on 4S and a large prop[ may be a problem

Douggie

[Gerwin Brommer]

Make sure you "insulate" the points where the rudder/servo rods/cables exit/enter the hull.
If any "moving"metal touches the carbon you'll get radioglitches !!!!

[tiqueman]

Douggie, thanks for the compliment and mid 40s to 50 would be great.

Gerwin, thank you for the tip. I never though about that. Now I wont have to post about "Radio Problems" in the future.

Scott

[tiqueman]

Well, I got her back in the water today. She ran quite well. Had to adjust my strut setting quite a bit from where it used to be. I guess because of more weight due to the CF lamination and addition of a bulkhead etc. It seems to want to ride a lot more bow heavy, which to me doesnt make much sense. But I seem to have it just about right now. I havent gps'd it yet. But Id say shes just about 40. Ive got a few more "tweaks" to make.

I had a drive line issue w/ the motor coupler. I had to modify the motor shaft as the Proboat motor has a flat grove in it for the set screw. So the flat part of the shaft does not run out to the end. I filed it down because after adding the thrust bearing at the motor, the set screw for the coupler was not getting to the flat portion. Anyway, It looks and feels straight, no bump where the new flat meets the old flat, however, the coupler had a wobble to it. If I remove the thrust bearing and put the coupler back to its factory location, it is perfect. So, I guess the Proboat motor isnt getting a thrust bearing... for now anyway.

Other than that, I got my pull pull steering figured out. I simply took an aluminum servo control horn and drilled it out to 3/16. Then drilled and tapped the side for a 4-40 set screw. Worked beautifully. Ive still got to trim down the control horn (one of the tweaks)

I also installed thru hull pick ups and eliminated any water lines outside the hull. I temporarily stuck a pan head phillips screw in the top of the rudder to block that water flow. I will be replacing that w/ a button socket or cap head once I can locate one.

Im having an issue w/ velcro sticking to the epoxy I used to laminate the CF in. sanding it, wiping it w/ acetone... it goes down like its going to stay stuck and in 24 hours its curling up and coming off. I was using it for my batts as well, but Im not trusting it at all. So... Question

Should I install (epoxy in) trays for the batts to sit in and strap velcro the batts in to the trays, OR, can I just epoxy part of the strap to the inside of the sponson and secure the batts that way??? The batts do not sit flat in the sponson. They are a little to wide so they would be on a slight angle. At the piont they are flat, they are about 3/16 down from the top of the tunnel. If that makes sense.

Heres a couple finished (almost) pics.