MAC.84\CF Rigger

[MikeP]

Here are a few pictures of the turn fin.

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

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

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

-MikeP

 

[MikeP]

I had some trouble with the kevlar wraped boom tubes, the new roll of wax paper I just got stuck to the glue. I was able to soak it off in water along with a little rubbing and scraping.

The longer tubes were 19g befor wraping and 20g after wraping them with kevlar. Thats not much weight for what you get.

-MikeP

 

[grasshoppa]

hey mike. I've been doing alot of research on composite materials because I too am looking for alternative ways to strengthen and lighten my hull. anyway, on reading up on the data facts about kevlar, I read that the material is extremely sensitive to sunlight. You should give give those booms a nice coat of paint if any of those are going to be exposed outside the sponsons or hull. also have you figured out how much your boat will weight after everything is said and done?

Alex

 

[MikeP]

Hi Alex, thanks for the info on kevlar, I did not know that! I will be ok because most of the kevlar cf tubes are inside the sponsons and hull. There is a 1" stub sticking out that I tape to. I will be sure to cover it all up.

I have been working on the transom. I like to square it up and glue in in place to start. Then drill holes in the side for dow pins made from tooth picks.

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

The next step is laying in the CF cloth for looks and reinforcement of the glue joint. I make a wooden block to press the cloth in and squeeze out the extra epoxy. To get a nice glossy CF look and keep the wood from sticking I make a mylar insert. When it's all in place use clamps to press against the wood block.

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

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

http://69.27.9.16/mikep/cf90/transcf1.jpg

http://69.27.9.16/mikep/cf90/transcf2.jpg

-MikeP

 

[MikeP]

Here is a picture of the transom with 2 layers of CF finished on one side. I will do the same on the other side.

http://69.27.9.16/mikep/cf90/tranfinished1.jpg

http://69.27.9.16/mikep/cf90/tranfinished2.jpg

-MikeP

 

[Hammerhead]

Hey I like the way the turn fin looks Mike. I have always thought about making one with a round bend, but I always end up with distinctly straight angles. Let me know how it works.

Hammer

 

[MikeP]

I have been working on the front sponsons rear boom mount clamp. I used a piece of round delron. Then stacked some sheets of mylar next to it to make the clamp a little under sized so it would pull down hard on the boom tube. I used sculpting clay to fill in where the delron rod curves under to keep the sides straight. Also use clay to hold down the mold pieces to the glass.

http://69.27.9.16/mikep/cf90/mountclay1.jpg

http://69.27.9.16/mikep/cf90/mountclay2.jpg

I mixed up some epoxy with powdered graphite and made a gelcoat to coat the mold with first, let it set up untill it was really sticky. I then layed up 4 layers of CF and into the vacume bag.

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

And a picture of the inside transom finished with CF

http://69.27.9.16/mikep/cf90/transfinish3.jpg

-MikeP

 

[Tom v.d Brink]

I love watching these projects you keep making mikeP.

keep up the nice work.

Maybe the question has been asked before but how many layers of CF do you need to lay up to make a non flopping turnfin?

Tom v.d Brink

 

[MikeP]

Thanks Tom,

I use 10 layers, Terry Keeley uses 11.

-MikeP

 

[MikeP]

Here are some pictures of the finished boom clamp. It weighs 8g.

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

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

-MikeP

 

[Twin_k90]

MIke,

Love your work!!

that boom clap looks great, my whole twin is made of kevlar, i havent had any problems with the sunlight yet,

Dale

 

[MikeP]

Thanks Dale,

It seems to me that UV is bad for everything if you leave it out long enough.

Do you have any tricks to sanding the edges of kevlar, you know those anoying little fibers. I have the most trouble when I drill a hole in it.

Here are the latest pictures, I made a hole saw out of brass tubing by sharpening the end. I played around with it after drillilng out the sponsons. I was able to cut through some thin epoxy, and some thin plywood. The plywood got a little hot but made a nice hole.

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

I used some black epoxy and sealed up one end of the sponson tubes. The sealed end is on the outer side and will blend in with the sponson side.

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

Here is all the pieces roughed in, I got some fine adjusting and trimming to do now.

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

-MikeP

 

[Twin_k90]

I know the problem, when i was doing the holes for the shafts on the twin those fibres were pissing me off, i ended up grinding to shape with the dremel and then using a xacto knife to clean up the edges, once it is wet with resin again it will go hard again,

thats the problems with kevlar and carbon!!

Dale

 

[Mike Bontoft]

OK now I have my plug finished I am wondering which is better to make my mold out of , epoxy or polyester ? I am thinking because of the pin holes you get with epoxy that polyester might be better, what do you think. Am I right epoxy can go over polyester but never polyester over epoxy?.

Thanks

 

[MikeP]

Mike,

This is how I was told to do it, I know it works, I would stick to epoxy for everything. To get a nice finish on your mold you need to use aluminum powder or graphite powder, I found graphite powder easier. You need a thickining agent called silica to make a thick paste refered to as mayonnaise. Brush this on and let it set up untill it's really sticky. This will give you a perfect hard surface on you mold. Lay up some light glass cloth, it will stick down real easy to the gel. Then start laying on the heavy glass cloth and wood if you need it. I am a novice at this and have had three molds come out perfect.

Go to this site and read "making a fiberglass mold".

http://www.cstsales.com/articles_for_model...el_builders.htm

-MikeP

 

[Mike Bontoft]

Thanks Mike

I have both the graphite powder and the silica. Wish me luck.

 

[MikeP]

Not too much to show today, The USPS truck showed up today with my tune pipe and rudder ;D. I got all the hardware holes drilled. I glued carbon tubes through all the foam core bulkheads for controll rods to pass through.

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

Trimmed and polished carbonkevlar tubes. Set up the sponsons and glued all the tubes in.

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

Good luck Mike, I am sure it will work for you!

-MikeP

 

[Don Templeton]

HEy Mike:

Can't get the last pictures to come up. Is that just me?

 

[MikeP]

Don,

It's not you, It's me. It's just one of those computer things that happens now and then. Something strange is happening about the same time on weekends, but not every weekend. The power goes off and the ups runs down ???.

Try again, It's up now.

-MikeP

 

[Fuss]

I sure wish you would hurry up and get that pile done! I wan't my friend back!