AC120 vs AC100 vs VOR70 - first try

Lurking around the hobby for a while now, and reading a lot of building log thread, I have decided to take the plunge and build myself two identical R/C sailboats. To be honest, I am not sure if I am up to the task. Everything involving wood, metal, sail and rigging should be OK as I am an organized and methodical mechanical engineer with lots a patient and… small hands. The fiber/epoxy thing though seems to be another ball game, where a clock is always ticking and you can’t afford a second try. Not sure I can forecast myself performing well there. But I will never know if I don’t try :confused:.

Anyway, I now have to choose the drawing of my boat(s). I have read Claudio’s eBook on how to design its own sailboat. Very interesting stuff. But for a first try, I would prefer to stick to a well-tried design. This brings me to a set of questions. A premise first, I am not looking for optimum performances. In fact, I don’t need or want to adhere to some class rules. I just want an all-around reliable boat to race in private with friends and relatives (I may be ending building or make them build more boats if it’s a success). If my building is a success and if I am then completely hooked, only then I will consider classes and performance.

I am going for an AC or Volvo look. So, considering my premise:

  1. Will either an AC120 or AC100 from Claudio be a good choice? I mean, could they be good all-around boat that would allow some manufacturing mistake here and there without being completely un-seaworthy? Or are they Formula 1 type, not to be touch by a newbie builder or sailor because they push the design envelope to the edge?

  2. Beside their storage and transport footprint, is there any advantage to go with one of these two in particular? Like in aquariums, a bigger one is easier to maintain due to the inertia of a bigger volume of water. It’s more forgiven to mistake and outside conditions. I guess the question should be divided in two, as I can see that the balance of plus and minus could differ from a building to a sailing perspective.

  3. If any of you is familiar with the VOR70, design by Francesco Bussi, this is the third boat I am considering. Do you know if it’s a good all-around design? The only guy I have found who built it did it with a canting keel, as in its 1:1 big brother. Francesco’s drawing doesn’t specify if the drawn fin and bulb are optimized for a canting or fixed keel. I don’t want the complication of a canting keel for my first boat so these drawings could be useless for me. Someone know the answer to this?

Hopefully, your insights will help me choose the “winner” between these three. Keep in mind that I don’t want to know your choice, but the why behind your choice.

Thank you so much for your time,


Hi SYmont,
my simple answer, AC120 as TNZ or Areva or Alinghi or similar models, have room for ‘mistakes’ inside the minimum weight of 4500g, some AC120 are reaching 4700g.
AC100 requires more expertise since the weights need to be controlled more carefully, this is normal when the size of the model is reduced and the weight is sitting below 3000g unless you go for an AC100-C specially developed for Canada hurban shallow waters.


Hi Symont, being a student of Claudio D fully support his recommendation of going with 120 …but be careful they are addictive if you get bitten by the bug :slight_smile: after starting two years ago I’ve now five.

Both of these AC boats are very good & the only real deciding factor between the two is their size

AC 100 requires very good light weight construction & is little more diffulcult to fine tune as a first timer the 120 offers greater forgiveness if your construction is not quite right.

I’m of the believe the 120 can sail in wider wind range than the 100 depending on you bulb weight ratio that you use and are little more stable in rough water, not so prone to bobbing around which can upset sail performance.

Cost of construction is roughly the same but the AC 120 is faster than any 1 metre including IOM.

Like yourself I had no experience working with epoxy & hand laminating, the first time can be little stressful working in the unknown, then after that you will find it a real breeze, we all make mistakes …it’s the only way we learn.

I love the VOR 70 as well and would like to build one one day with canting keel however I will need to get past my AC mono-hull passion first …loads of people here to give you helping advice

Cheers Alan

What he said :slight_smile:

The 120 is a gracefull boat, with good build logs to follow. Several building techniques will have to be learned, but not mastered, and finding some construction material will be a challenge.

But the result is spectacular.


Wow! Claudio and Alan back to back, my two top gurus. I guess I am in good hands here!

You both really understood my concern and I couldn’t be happier with the outcome. The AC120 clearly seems to be the appropriate choice and I can now start looking forward without any regrets. I will probably go with the ETNZ since it has the more elaborate sets of drawings, building logs and design discussions such as the CLR and CE lead.

I guess I’ll be reading the ETNZ IACC120 Dual build thread tonight… again.

Seeing your results Alan, it’s hard to believe you didn’t had any experience with epoxy and lamination prior to this. Even if it says nothing on my hopefully latent skills, this is still a good inspiration.

Have a great day,


[edit] Thanks also to you Mike.

Hi Symont, thanks for the compliment but I would not put myself anywhere near Claudio skills and talents :rolleyes:

You will find all of Claudios plans have all the info you need, hence look at type of design that you really like, Claudio can help with further detail you may require.

Here’s another build log on NZL 32 using slightly different construction technique than my first ETNZ when it comes to first time epoxy laminations my advice would be to practice first the steps involved & be prepared to scrap the first hull just to get the feel & see what is involved.

Cheers Alan

Hi Alan,

You may not be at par with Claudio’s design and building skills, but you are certainly as generous of your time as he is in sharing your experiment. Claudio give us the core expertise (invaluable, I agree), and your building logs answer most of the questions we, newbies, would/will have along the way. To me, both your contribution are equally important, helpful and… well appreciated.

Your advice on epoxy lamination is well taken. I had already read your other thread. The latex lamination technique looks appealing, especially if you think about weight and a faster way to build them. But for now, I see it as another way for things to go wrong! Trying to apply the proper and constant tension without moving anything seems to be quite a challenge. The good thing is I could give it a try with the same male plug. This and trying a female mould open at both ends.

I have read in one of your regatta report that someone had an AC120 planked with 2mm mahogany with a simple epoxy paint on it. That seems like an easy way to do it. Am I missing something?

Again thank you for your time.


Hi Symont,

I’m always looking for easier ways to laminate, Latex is unbelivably easy and found that you need the least tension as possible gets the best results …too much tension and the weave of the cloth shows up but best of all only takes 20 mins.

After seeing Claudio using packing tape over one of his male plugs I figure this another step in the right direction that eliminates waxing and PVA release for mould prep before laminating & saves few more bucks along the way too. I had one hull which looked great only to find later that I did not have enough release on the mould and ended up destorying both the mould and the hull trying to get them apart, later realised my PVA release only had 6 month self life, which had expired :rolleyes:

Mauro Folicaldi is the skipper of Areva FRA-93 (pics attached) with the mahogany hull I was talking about, the best finished hull I have ever seen, made by a boat builder in Italy (don’t know is name, maybe Claudio does ?) made the hull for him. Mauro is top skipper to boot and wins his fair share of regattas.

The only thing about planking and epoxy coating the hull is that if you want more than one boat you need to do it twice, hence laminating off a single male mould cuts your construction time considerably.

Cheers Alan

Hi Symont,

I can honestly say, if you want great performance, go with an AC120…

A wide style VO70 stye hull without a canting keel will not match the AC 120.
If you did want to go all out, I have a spot on canting keel/canard design that is 4th generation tested and will suit your needs in a VO70 style yacht… But that is not where your headed yet I think…
My personal experience is that although spectacular to watch when reaching, a canting keel yacht is also more complicated to build & optimise and has higher maintenance demands.

So following on from your remarks, I would defiantly recommend the AC120 out of the three as I feel it will give you the satisfaction you seek once on the water plus the design is nice and flexible - it has a good margin weight wise for a beginner to experience some trial & error.
Ultimately the choice is yours and you have a great list of people here you can draw experience from… Good luck!


Very good point Alan. I guess my apprehension about epoxy lamination made me forget that planking with epoxy coating means starting over again for the subsequent boats. I guess I will have to build the nerves to try wet lamination.

Packing tape is now noted in my planning booklet.

I have read again your “Latex for laminating moulding process” thread. If I understand correctly, and nothing have changed since then, you are using a 100cm latex sheet to cover a 120cm mould. Does this roughly represent the desired tension, in all direction or you’re going for less tension these days?

I am glad you chipped in Jim on the VOR70. I really like the Ericsson 2005-2006 but I would prefer to start with an easier building project that will also be more easy to sail afterward. The ultimate goal is to have a couple of boats to start a small unofficial club here and the AC120 seems to fit the order. If I don’t burn my interest in this project, I will hopefully had gain the experience to tackle a VOR, which will only be better.

Happy sailing!

Nothing has changed & based on using .50 mm latex I’m guessing that 20-30% stretch tension gives the best results, what I’m looking for using this process is to “trap & not squeeze” the epoxy out of the weave to have smooth, even finished surface. Using transparent latex helps see any small air bubbles under the latex so you can roll them out after lamination.

To gain first experiences using epoxies, I would really suggest to just play around with it using A4 size samples firstly on various forms like PVC drink bottles & trial few layers @ different angles etc just to see how it handles and reacts and take notes on temperature, humidity and how it takes before the epoxy goes off, then you will be good to go when it comes to your hulls.

Cheers Alan

You will be happy to read Alan that you got me to a point where I am looking forward to give it a try :D.

Today has been a bit of a downer though, when I found out about the price of the proper resin and fibers. Well, at least relative to my budget. It doesn’t compare to the cheap stuff at my auto part shop. Nevertheless, the project is still a go. I will just have to figure this out along the way.

So… one last round of thanks to Claudio, Jim and Alan for your time and guidance. It was more profitable than I was hoping for. I will now plan my project and my resources properly and, hopefully, come back to you with a new building log thread.

Happy sailing!

Yup, some of the costs can get you down. I used one of the smaller cans of west systems resin, and the slow hardener. Cost was about 60 dollars, but it did the whole boat. But then add in the pumps,and maybe go pick up a mini scale from the convenience store… And you are up to 100, so I see where you are coming from.

The two other big costs ar the winch, at about 60, a meter of carbon fibre cloth at about 50, and, in my case, an over engineered mast…but I love it.

To start, however, shadows, and planking, it is not too bad.

This, too was my first model, and first time working with resin and fg. I goofed around with it briefly, but the dual build thread, and some west systems videos, gave me the confidence to go for it. The fg you put on the plug is the big learning experience, and nothing that filler and sand paper cannot fix. Filling the weave was my challenge, still is, latex can help there, but it is another skill to learn.
Then I just used part all wax and the hull came right off.

Any questions, just ask or pm me. I am just on province over!


I’m a complete noob and am about to glass an AC100d hull. The plug has so many mistakes that need filling etc. but it doesn’t really matter as I’m having a blast doing it. Like you said, there’s so much info on this site and people are really helpful so just go for it.

I can’t even find West systems out here so I’m using the local fibreglass guys stuff. No-name brand is ideal for me so when I mess it up I haven’t blown too much money :rolleyes: When I’m better at the laminating I’ll buy the carbon cloth etc. and get more hectically involved with weight watching. I reckon spending the money on electronics and mast/sails etc makes more sense for someone like me as those can be moved over to a new hull which will hopefully be better than my first attempts.


Mike and Andrew, your pep talk is well appreciated. This forum transformed my anticipation for the lamination process from frightening to stimulating.

Now that I am really committed to this project, I am reading lots and lots of threads while finalizing the different aspect of my planning. There is so much info there, and the community is so feverish to help anyone in needs, that I am sure that I only need to show perseverance (and some cash;)) to assure a great success at the end.

Good to know that you, and all the others, will be there when I am puzzled with something.

Happy sailing!