IOMICA Forum

Hello to All

I'm starting to build my first IOM boat wich will be an "Arrow" Lol

I've studied the drawings from Anders Wallin's (CAD Version 2003Nov27) and Ch-H Détriché's (Original) and i've found some problems:

The drawings bring only the diameter of the Bulb.

- How can i find or calculate the rest of the Bulb measures?!

- Is it possible to buy one!?? If yes... where can i find it!??

I confess that i don't understand how can i work with "Bulb Calculator" to sort things out and i don't have the tools and skills to mould the bulb (wich is a risky operation...)



Keel and Rudder materials and building techniques

- Is it possible to buy the keel and rudder too!? I never worked before with materials like Fiber Glass and other "modern" materials that are used on boat construction...
Any alternatives!? Is it possíble to build an 100% wooden boat!??

Thanks in advance to All

- Is it possible to buy the keel and rudder too!? I never worked before with materials like Fiber Glass and other "modern" materials that are used on boat construction...
Any alternatives!? Is it possíble to build an 100% wooden boat

Most rc yachting suppliers are able to supply all of the bits you have mentioned

It is possible to make a 100% wooden boat but personally I think this could be more difficult than using “modern materials.â€

Hi Signatus

Like yourself I am new to making yachts so I have been experimenting a little. I have discovered that with epoxy resin you have to get the ratio exactly right otherwise it remains gooey. I also found that it can go off too rapidly unless you spread it out after you have mixed it. I also found that glass cloth works better than chopped strand mat.

I made some test patches on a sheet of curved plastic to work out the weights for various methods of construction and to check that the release agent worked ok.

I am making a Polyfiller shape on a fiberboard core. Its dirt cheap and easily altered. Some constructors say that they use an expanded polystyrene mould since it is very quick to file down. I use polyfiller since I make mistakes and I can dollop on another layer if I remove too much. Polyfiller is slower since you have to add a little at a time to let it dry thoroughly otherwise it cracks. Even that is not a problem since you can chase out the cracks and add another layer.

I am feeling my way at the moment but perhaps others on this forum will suggest better ways of doing things.

I will be watching your thread with great interest.

Good luck!

Jamestj wrote: Some constructors say that they use an expanded polystyrene mould since it is very quick to file down.

I will be watching your thread with great interest.

Good luck!

JamesTJ take a look at this 2 links

http://el-servo.physics.helsinki.fi/per ... 001_11.htm

http://el-servo.physics.helsinki.fi/per ... 11_nov.htm


I'm thinking on using the first one has "inspiration" to my work. The only problem right now is finding where i can find Fiber Glass...

I'm using AutoCAD to "tune up" the drawings and when their finished i'll jump into moulding the boat using the first link method, using an expanded polystyrene mould. It's easy to cut with a Hot Wire and stuppidly faster than rigging shadows with balsa wood.
I forgot one and most important... CHEAPER!!!

Any other ideas!? Or Sugestions!??
Thanks to all again

Hi Signatus

Thanks for the links. It is interesting to see other people's work. Fiberglass and resin are quite easily available but web sites will do mail order quite efficiently.

We would probably go for epoxy resin in your case. Although it is more expensive, it is more rigid so you would be able to put more tension in the rigging. Neither does it emit harmful vapour like polyester. We are using The West System - a fancy name for mixing the two epoxy components in the correct quantity using syringes. For school use it is foolproof. It is not the most rigid resin when set but it is one of the stickiest. This is important for our project since we are using a sub frame to tension the riging. We don't know if this is the best way of doing things since we don't know of other constructors using one. We like to be different. Working out the forces on a subframe is an interesting exercise.

We are envious of industries with large CADCAM machines. The school only has an A5 sized 2D machine so we have to break the project up into little bits which can be made on the small machine.

Good luck!

Thanks for the Tips JamesTJ !!!


Can you post here some of the links where i can find the fiber glasse's / epoxy's ???


Where can i find aplication / use instructions!??

It would be usefull not only for me but to everyone else in the same situation than us


--- /)-------
/)

Merry Christmas to you all!!!!
Happy New Year

Signatus wrote:Thanks for the Tips JamesTJ !!!

Can you post here some of the links where i can find the fiber glasse's / epoxy's ???
Where can i find aplication / use instructions!??
It would be usefull not only for me but to everyone else in the same situation than us
Merry Christmas to you all!!!!
Happy New Year

start with SP-systems guide to composites:
http://www.spsystems.com/solutions/gene ... osites.pdf

they also have other documents that might be of interest:
http://www.spsystems.com/solutions/general.htm

Can you post here some of the links where i can find the fiber glasse's / epoxy's ???

You could try:
http://www.cfsnet.co.uk
http://www.fibretechgb.co.uk
for laminating supplies. I have used them both and found them to be very good.

If you intend to use foam to make a mould you will have to use epoxy resin because polyester resin will melt the foam. Also treat it with respect and use barrier creams and protective gloves.

Please keep us informed of your progress. I have found building yachts very rewarding and enjoyable and there is nothing quite like the feeling you get when you start to win the odd race with your own creation.

Chris

Hello again Spaldi01!!!

Thanks for your help!!!

Now i'm working on redrawing the Arrow via AutoCAD. This will help me understandig the boat and it's forms before any assembling.

I read on Blowfly web site that Polyester resign are less stronger than Epoxy... and they get soft with the Sun... is this true????

How thick is the Epoxy!? 5mm?? 3mm??

For a IOM boat... how much u need to buy!??

What is your favorite!?? (i confess i'm still taking my very first steps in this "material world"

Hope to read more news (and help...) from you soon

Thanks!!!

Signatus wrote:Hello again Spaldi01!!!
Thanks for your help!!!
Now i'm working on redrawing the Arrow via AutoCAD. This will help me understandig the boat and it's forms before any assembling.

you should be able to import the DXF file from my website directly into AutoCAD. If you then want to do some modifications you probably need to redraw the boat using autocad splines or something similar.

I read on Blowfly web site that Polyester resign are less stronger than Epoxy... and they get soft with the Sun... is this true????

epoxy is around 20% stronger than polyester.
epoxy will get soft in the sun too. most that I have seen have critical temps around +50to +60 Celsius. Epoxies with even higher temps are available but very expensive (fighter planes etc. are made of this...)

How thick is the Epoxy!? 5mm?? 3mm??

the SP-guide contains a formula for laminate thickness. Most IOMs are laminated with 2-3 layers of ca 150g glass cloth and the final laminate thickness is 0.5mm or thinner.

For a IOM boat... how much u need to buy!??

When laminating carefully we have found that about as much resin in weight is needed as the fibers weigh. i.e. if you have one square meter of 165g cloth then it would need 165g resin.

What is your favorite!?? (i confess i'm still taking my very first steps in this "material world"

most people use epoxy for boats and fins.

Hello again...

i've found this one on Fibertech's web site:


(...) Finishing Epoxy Resin (With Hardner)

Notes:

- Mix Ratio 2:1 full depth cure
- Pot life 45mins
- Cure time 24-36 hours
- Can be heated up to 50° to reduce the cure time. (warmer makes it less viscose)
- Non shrink tack free glossy surface finish super low viscosity. Once the resin has cured the resin will become totally fuel proof.
- Ideal for surface finishing on model Aircraft and Boats where a crystal clear finish is required or alternatively the cured resin surface will accept all paints.
- Can be used in conjunction with Glass, Kevlar and Carbon Fibre.
- This epoxy resin will not attack foams, white, pink or blue. (...)


(Is this the Foam that is used to mould the boat!? The one that this Epoxy don't attack!??)

Exp:
http://el-servo.physics.helsinki.fi/per ... 001_11.htm


Fibertech's Finishing Epoxy Resin (With Hardner) (as shown on Fibertech's website)



Any commments!??? Any previous experience!???

Thanks everyone!!!