Well after doing a little thinking, it occured to me, that the RG65 would be a perfect 1/24th scale TP52. Since we all know my affliction with them you can bet my first RG will be quite TP52-esque.


Hi folks
I am from Germany (my written english is not the best) and read the RG Threats postet in this Forum. Since last Year i tried to design mi own RG and learnd a lot. At the beginning i had the same Idea about scaling down a TP 52. But there are 2 Problems. 1st the Displacement (scaled down on 65 cm) with round about 600g (the german Rgs have Bulps with 500- 560 g). The other Problem is the Hullshape and with. The international Development tends to slim Hulls (12-10 cm) with a even slimmer Waterline. The wetted area is absolutly crittical for the Performance of such a small boat. A design like the tp 52 has a lot ot wetted area. The other fact is, the Part of the rightig moment generated by the Hull decreases with scaling downand. But wenn heeling a hull like the TP52 the new Waterline is asymetric. For that reasons i dicidet to choose a slimm design (like aM Boats). But this depends on your aims (condition, looking and for races?). But a rg 65 TP sounds verry nice and it will look as well. In windy conditions the negative facts will be compensated and a TP could performe verry well. When i have my recent Project i think about building a Boat special for windy conditions inspired by the recent TP2

kind Regards from germany

Sven & Everyone -

I’m still trying to correlate the differences between Microns, Mils, Millimeters, and Gauge/MM/Inches (decimal or fractions) for thickness of materials. Add in some builders who refer to weight in grams and some in weight per ounce and I am completely confused. In some cases the manufacturer also creates misunderstanding by listing a material as .003 but nothing more - so do I assume this is in Mills/Thousands?

I see where many of German, and some Spanish as well as South American sails are from a material called UL-Mylar. Some are using florist wrap - but don’t specify it’s thickness/weight. Others are using acetate, some Mylar, some ripstop nylon, and some Polyester (PET) material.

I cannot find a source for the UL-Mylar product here in the U.S. - nor can I determine what it’s real thickness/weight is.

I am going to post a line drawing of a sail that might even be a typing error - but this all adds to confusion for those of us new to the class and building without have a local competitive boat to compare against.

It would be helpful for those with other language skills to help decipher some of the forum posts to help us understand. Is .002 Mylar too heavy? Is TriSpi 25 too heavy? and so forth.

Thank you for posting to this forum. We all appreciate information so our first building efforts are competitive.

Dick :smiley:

Polyester film (Mylar, PET, Icarex, florist wrap etc) has a specific gravity of about 1.4 (btw Spanish speaking countries would write it as 1,4), so 50 micron weighs approx 70 g/sq. m; 35 micron, 50 g/sq. m and 25 micron, 35 g/sq. m. I haven’t checked, but I’d guess that ripstop (tightly woven Nylon) is similar.

Here’s part of a sail plan, with the dimension I had posted earlier in the RG65 thread. It has many completely confused.
In the thread I believe you or Maximo “guessed” at 25 or 35 … but it sure doesn’t help new builders to “guess” what the specifications really are. I’ve provided these to a couple of different US sailmakers and they shake the head and shrug their shoulder. I suppose I can always use some of my 9 oz. big boat Dacron, but have a hunch it might be just a “tiny bit” heavy.

Any thoughts?

I think you’re just going to have to put the “0.5” micron Mylar down to error. It’s probably not the first time plans/building instructions have included a mistaken figure, though, as you say it is inconvenient.
25 micron is about 0.001 inch and I’d say that is really the minimum practical.

Apologies to Millrtime and the rest of you for my hijack of his thread. I am sorry for taking it off course and discussing sail material weights for the RG65. When I posted, I thought I was still in the RG6 thread and didn’t realize until just now that I am in the wrong thread.

Sorry guys. I did find some new potential sail material. It will be posted in the proper thread.

:scared: :headache: :blush: Dick