MAC.84\CF Rigger

[Ian Inverarity]

MikeP,

Interesting stuff!

My hummingbird hydro has 1/4" ply sides that are laminated on both sides with a single layer of carbon cloth, looks like about 5.7 oz cloth. Vacuum bagging was used. The floor looks to be one or two layers of carbon and very thin ply, about 1/32". The bulkheads look to be the same as the sides. The whole thing is increadibly light, but I dont know how strong it is, I have not crashed it!

Do you put the moulds inside the vacuum bag? There would be less risk of distortion of the mould.

Ian.

 

[MikeP]

MikeB,

Sounds like you a getting a nice set up there, I could use a new large bench this hull is long. All my other projects have been 2.5 and 3.5 boats. You were smart to get a vacume switch too much vacume can crush your project. I use 8" vacume. The higher the vacume the less pin holes you will have.

-MikeP

 

[MikeP]

I made a quick drawing in MS Paint showing how the boom tubes are done. The yellow is the outer tubes wrapped in kevlar and glued into the sponsons. The one in the hull-front is glued in place, the one in the hull-rear is clamped and adjustable up and down. The riggers in Japan use aluminum tube for the outer tubes instead of kevlar/carbon tube.

http://69.27.9.16/mikep/cf90/boomassy.bmp

Here is the idea, if you hit something hard enough you break the inner carbon tube, the sponsons and hull should not get damaged then you just slide a new inner boom tube in.

-MikeP

 

[MikeP]

Ok, Here is how the sponsons attach to the inner tubes.

http://69.27.9.16/mikep/cf90/tubedetail.bmp

The red piece is glued to the inner tube. then tape is wrapped around the yellow and red holding it in place. You can make the red piece by just wrapping tape. Once I was happy with the setup I made the red piece from carbon tube and glued it on.

-MikeP

 

[Twin_k90]

Hmmm dont know weather i would trust some tape to hold the sponsons on at 90+ mph, maybe on a 21 and 45. i think i will stick with the half tube and some sort of bolt system.

Dale

 

[MikeP]

It's time to make a hull. I prepared the mold by sealing all the cracks with wax and taped the edges with tape to keep the epoxy from seaping behind the mylar and sticking to the bare wood.

http://69.27.9.16/mikep/cf90/wax.jpg

Here is a picture of the new bag with the ez-vac bag connector and quick lock bag seals.

http://69.27.9.16/mikep/cf90/bag.jpg

Cutting the cf with the rotary cutter makes nice clean cuts.

http://69.27.9.16/mikep/cf90/cut.jpg

This is how the mold looks with the 3 layers of CF then mylar on bottom and sides then breather cloth no epoxy yet.

http://69.27.9.16/mikep/cf90/breather.jpg

I mixed up 2 pumps of epoxy and poured it on the mold spread it evenly and layed in the first CF. Squeege it in with a body filler spreader completly saturating the cloth. Mixed 2 more pumps epoxy did the 2nd. Same for the 3rd. then mixed 2 more pumps and wet it down good. It sticks pretty good to the mold now.

http://69.27.9.16/mikep/cf90/wet.jpg

Place the mylar in and stick it down good, make sure none of the mylar sticks out or above the mold. Then lay down the breather cloth. There is now going to be breather cloth under the entire mold and down the center to help the vacume reach all areas.

http://69.27.9.16/mikep/cf90/ready.jpg

Toss it in the bag. You have to help the bag down into the mold and keep things in place.

http://69.27.9.16/mikep/cf90/bagged.jpg

Here is a picture with the bag sucked down. I use a small wall paper roller and roll all of the sides bottom and corners to help smooth out the hull a little.

http://69.27.9.16/mikep/cf90/vacumed.jpg

 

[Propjockey]

Mike--what epoxy are you using?

 

[Hammerhead]

Hey Dale! There is a technic to doing the tape right. It will hold, even at 90mph. You have to do it right or it will slide. If Mike could show you the little trick he designed for the .21 you will see what I mean.

With just tape, use electric tape. wrap it around the sponson boom so that it becomes the same diameter as the outer tubes, then cut it. Then tape over the top of the outer tubes and the tape that you wrapped around the booms. Make sure you wrap the tape so that the end cuts edge is faced toward the back of the boat, or it will unwrap itself. It will hold, guarantee it. If it slides a bit after a few runs, replace it. Electrical tape is a lot cheaper than carbon fiber pipes. If you are using the graphite pipes you are wasting your money. If you can get the woven fabric over graphite type, they are a lot stronger. They are a bit heavier though. Graphite pipes bird cage when they break. Can be a little bit dangerous for the guy who is retreiving the boat as well. I find that roughing up the surface with a few swipes of 300 grit will keep the tape from sliding.

Even though your boat is a twin, I think my single engine hammerhead was probably heavier, and it held with tape all day long.

Hammer

 

[TomMoorehouse]

wow mike..... looks great! ill bet it is a lot harder than it looks!

 

[MikeP]

Mike--what epoxy are you using?

This picture should answer your question. West Systems has all the cool stuff.

http://69.27.9.16/mikep/cf90/west.jpg

Tom,

I would say it's not as hard as you think. Make a good mold, the rest is easy. The guys who layup fiberglass, CF without a vacume bag are the real artists.

-MikeP

 

[MikeP]

I pulled out the hull from the mold. This piece turned out good enough to be visable so it will be the top half. I will trim the mold the so the next one will fit inside.

http://69.27.9.16/mikep/cf90/side.jpg

http://69.27.9.16/mikep/cf90/out.jpg

http://69.27.9.16/mikep/cf90/top.jpg

-MikeP

 

[Tony Jacuzzi]

This is an extremley interesting thread to me. I was really curious Mike if after you trimmed the piece if you could weigh it, then we could track the building process and the final weight and see if there are any savings etc. to be made in certain build processes. I would also like to know the dimensions of the tub (L-W-H) etc... Thanks Tony J

 

[Twin_k90]

Mike,

Awesome Work, it is going to look the goods dude!!

Hey Dale! There is a technic to doing the tape right. It will hold, even at 90mph. You have to do it right or it will slide. If Mike could show you the little trick he designed for the .21 you will see what I mean.

With just tape, use electric tape. wrap it around the sponson boom so that it becomes the same diameter as the outer tubes, then cut it. Then tape over the top of the outer tubes and the tape that you wrapped around the booms. Make sure you wrap the tape so that the end cuts edge is faced toward the back of the boat, or it will unwrap itself. It will hold, guarantee it. If it slides a bit after a few runs, replace it. Electrical tape is a lot cheaper than carbon fiber pipes. If you are using the graphite pipes you are wasting your money. If you can get the woven fabric over graphite type, they are a lot stronger. They are a bit heavier though. Graphite pipes bird cage when they break. Can be a little bit dangerous for the guy who is retreiving the boat as well. I find that roughing up the surface with a few swipes of 300 grit will keep the tape from sliding.

Even though your boat is a twin, I think my single engine hammerhead was probably heavier, and it held with tape all day long.

Hammer

Hammer i dont think your boat will be heaiver than mine, ask Timbo how heavey it is!! if a sinlge was this heavy it would never get on the plane! i might try the tape on a 45 hydro when i get it built,

 

[TimD]

Hammer,

Dale's twin is definately too heavy for tape. The thing hurts my arms to launch and retrieve it. Not to mention the hose down I get when it launches :

The twin is now turning very well after a few weeks of testing different things and it would be too much for the tape. Plus the extra weight of the screws is next to nothing on this beast. Reliability is more important.

Tim.

 

[Hammerhead]

Gotcha Tim!

Hey Tim! I think I stirred up some of Mikes brain cells with the bladder tank. I want to send one to him, but I'm out right now, so I can't measure it. Dale has 3 of them. Could you get him to post the measurements. This way Mike can see if it will fit his new rigger.

I think the measurements are printed in millimeters on the box.

Dale, have you ever thought about using solid carbon rods for your booms. Doubt if you could break them. They would be the way to go if weight isn't a factor. Then again, if weight isn't a factor, you should just use aluminum pipe.

Hammer

 

[Twin_k90]

Hammer,

Im house sitting for a mate at the moment so next time im home ill get the measurments for you!

at the moment i have 6061 T6 solid aliminium booms in there, they are very heavy, but even they still bend, i thought i was going to be changing them yesterday after a rather large wave decieded it was going to play and pull the front under the water,

Thanks for all your help tim, i really appricate it! with out it i dont think the bitch would be turning and would have a large hammer through it!

Dale

 

[MikeP]

Got a turn fin in the bag tonight, here is a picture of the mold. It is made with foam then mylar sprayed glued on. Layup 10 layers of CF, 5 of the layers are cut at a 45deg. to the weave. Lay them every other one. This makes a non flexable piece.

Thanks, Twin_K

http://69.27.9.16/mikep/cf90/finmold.jpg

-MikeP

 

[Twin_k90]

Guys, here are the bladder tank sizes, since is a .84 you could get away with a 14oz tank,

400-s 14oz, 58 H, 54 W, 178 L

400 14oz, 63 H, 58 W, 155 L

500 18oz, 70 L, 65 W, 165 L

Dale

 

[Hammerhead]

Hey Dale! Where did you get the 14oz.

I have only been able to get 18oz from Shimizu.

Hammer

Hey Mike! Try this call sign. He is a guy I work with. His name is Shimizu, but not the same Shimizu that I get boat stuff from.

JE1LFX HF all band.

Hammer

 

[MikeP]

Got a nice piece of stock to make the fin out of.

http://69.27.9.16/mikep/cf90/rawfin.jpg

Tonights project is a turnfin mount, the mold has a 45deg. angle cut in it. The finished mount will have a lip bending out at 45deg. This should help reduce twisting. This is 10 layers CF.

http://69.27.9.16/mikep/cf90/mountmold.jpg

Tony,

The hull is 43" long 3.5" wide about 2.5" tall. I will be picking up a triple beam scale in a week or so then I can get some weight measurements. I usually only worry about transom weight.

I been wanting a scale to weigh epoxy for mixing, they say that is the best way. It's hard to mix small amounts in measuring cups at 5 to 1 ratio

-MikeP