DiasDePlaya

Hello everyone,

I'm thinking to build a IOM boat as here in Chile the IOM class is close to start.

I have little experience making toys using ther****rming method, but never saw a sailboat built this way.

My idea is to build a mold in the usual way and thenvacuumover a 1 mm PETG plastic.

Anyone have experience about? Suggestions? Comments? Advices?

Regards,

Jose from Chile

Morspeed

I have not seen this done, but would be very interested to follow your progress.

What sort of temperatures would you be using in moulding??

Dreamwakes

mfr02

HFM did their "Impala" this way many years ago.

DiasDePlaya

No idea, I just continue heating until I get the softness that I'm looking for, but I never used a termometer.

DiasDePlaya

That is the point why I'm thinking to build the hull this way.

About collisions, did you try to open a PETG display without a knife? Is close to impossible, this plastic is very strong. For example the R/C cars bodies are made in PETG and resist very hard impacts.

My only consideration is about how flexible is, this is why I'm thinking to use 1 mm sheet. The other solution is a inner 3D reinforcement structure that is easy to made after build the mold.

Islander51

Please note that IOM regs state that hulls must be made from wood or glass/resin.
This means that you would not have an IOM hull,but a one metre hull shaped as am IOM, made in plastic,
so no playing with the boys if they're doing serious IOM stuff (ranking events, Championships, etc.)
If that doesn't matter, then good luck!

DiasDePlaya

Islander51

I didn't know that ! Just goes to show how much I think I know, but in fact only know half of it !

And metal ; skin your hull with aluminium beer cans , I know where to get some of those !

mfr02

Regarding hull strength and collision damage, I well remember standing at the poolside at Fleetwood after the last Marblead World Champoinship, within earshot of Martin Roberts who had lent his boat  to an eastern European gentleman to try.  It had been swatted by something out there, and there was a sizeable crack in the (kevlar and carbon fibre) hull. The overheard comment was along the lines of "Me boat, look at me *oo*y boat!"

1967250s

There are some people making some sailboats with thermo forming, especially with smaller hulls like the footy's. Take a look on the search here and on rcgroups and rcsailing. Usually you would need some inner structure with larger sizes to help keep the shape, but it is very much alive, also with power boats. Do it and let us see it!

DiasDePlaya

I asked in the IOM USA forum, and PETG is not allowable as the IOMICA never did the list of permitted materials, then as the principle is that if something is not permitted by the rules then is prohibited.

Now I'm working in a RG-65 because the class rules said that all is permitted if is not prohibited by the rules.

aquajet

Hi
I think they dont understand or read the rules very well.
on page 13 of the class rules ther****rmed plastic is expresly mentioned in the list of materials for hull construction
We have a lot of vacuum formed hulls here in south africa competing. My first boat was such a boat, and was very comprtitive just needed a decent skipper. It was also a cheap easy boat to make.
Myself and a friend want to make our own design boat and use vacuum forming to get the cost down and attract mor to the sport, but we dont fully understand how to do it yet.
here is a bit of the rules

D.2 HULL

D.2.1 MATERIALS

(a) Subject to (b) and (c), the

equipment but including any supports and containers for such items, shall

be made of and joined using one or more of the following materials:

(1) metal,

(2) wood; wood based products containing only permitted materials,

(3) glass fibre reinforced plastic,

(4) adhesive,

(5) varnish; paint,

(6) film covering materials which may be fibre reinforced,

(7) elastomeric material,

(8) thermoplastic, which may be moulded, containing only permitted

materials.

hull, excluding fittings and remote control

DiasDePlaya

aquajet,

I asked to IOMICA and they answered that everything that is not allowed is prohibited, and as they never did the permitted material list every ther****rmed plastic is prohibited. The point (8) for now is a dead rule while they don't do the permitted material list.

aquajet

that being the case then all boats are illegal as there is no specific mention of the plastic that may be used in a "glassfibre plastic reinforced " type build. as long as it contains a minute amount of glass fibre any plastic may be used and they cant turn around and say i am missing the general idea , they make the rules. they are the pedantic ones.
There are a lot of the plasic moulded boats here and they all went through the measurer here who is also a stickler for the rule.

Lay up a few strands of glasson the plastic when it is hot while you mould it, they should stick ok, then it is glass reinforced.

DiasDePlaya

I think that the problem is that many people do money selling boats, and if someone can do boat ther****rmed would sell them very cheap, destroying a good business.

I don't have intention to sell boats, but probably somebody look like a menace if open the door to ther****rmed boats.

aquajet

Ithink someone is being ridiculous. Went and made some enquieries and Iknow a guy here who made plastic thermo form boats that sailed here and europe in high end competition and was not protested out, and those guys in europe can be petty. He used about a 1mm plastic as well and the boats sail very well and never cracked or broke.
Idont think they are trying to keep others in busness, and think if you spoke to the right guys, it would be fine. Anyway it is not as if there are so many boats that they need to keep people away. We make boats here in glass fibre at 1/5 of the price of some of the european boats, but they have never won a world competition so only the local sailors buy them. They sail as good as the euopean ones when you change around skippers. If you want to grow hobby in your area Iwould still make a boat , and just tell them it is not yet suited for international, then get the representative for the country to request rule clarification / change to allow plastic forming . Unless you are using a very unique plastic, Ithink the rules do allow it as the printed rule is what counts , and not what some rule boy would like it to say , when it doesnt quite say it. It does say
Here is a oficial interpretation of the rule. If your material does not come under this then try aply for it to be added showing it has low cost and good stuctural stength ....then it must be added..... carbon fibre ect was not allowed for cost reasons.

8. HULL D.2.1(a) (8) MATERIALS: "Thermoplastic" means "Softens when heated, re-hardens on

cooling". It is assumed that the rule permits vacuum formed hulls made from ABS PVC etc. but does

it permit more materials? Are "pellettised" thermoplastics with unknown additives (as in 1 and 2

above) permitted?

Answer:

Pelletised thermoplastics are allowed for the construction of the hull if they are in the compliance with the

class rule D.2.1(8).

Item 8:

DiasDePlaya

I known the appeal that you quoted, but it is from 2003, and some rule said that the appeals that are not included in the rules died automatically in 3 years, then the ABS is not legal by now.

Is ridiculous, but for now those are the rules.

aquajet

MMM
Ithink something is wrong.
Idownloaded that pdf off the IOMsite earlier today
The oficial rules are nearly 3 years old so will they also di
there are other things in the same document that still apply
You are bing misled by someone not wanting your boat in plastic, not by a body of people
If that rule doesnt aply anymore then they have to put a stop on it or a oficial recind like texalum, which is legal , but too dificult to prove it is legal, so rathere remove it.
That has never happened with plastic for a boat

DiasDePlaya

Please read this post in the IOM USA forum:

http://onemetre.sbmyc.com/forums/vie...r=asc&&start=0

aquajet

Well it seems all boats are illegal then.... the resin in the glass is not specified. in order to keep cost low epoxy types should be banned.......mmmm... maybe polyester should be banned
Maybe it is time to stir up things a little
Our nationals are coming ........perhaps a small protest or two would be in order
then the national regulator would have to request clarification
seems a lot of rules are then invalid as the interpretations are older than 2 years and the last rule pdf is nearly 2 as well

DiasDePlaya

Not all the rules died after two years, only the interpretations that are not included in the rules, then the interpretation about the ABS plastic is a valid material is died, but not all the rules.

I'm waiting that Chile be a IOMICA member to ask officially about PETG. Probably at the end of this year. For now nothing to do.