OK - the idea worked great, the process - not so much. Found out a major problem…
laid up as follows:
Plug
Covered with brown tape
Covered with epoxy/glass layer
Covered with another layer of brown tape.
PROBLEM: Brown tape is so thin, you can’t feel/see when it has all been removed. First layer of tape shows through. Need to make a process change.
STEP 2 - Revision…
2. Cover with CLEAR tape.
This will allow you to tell when the second layer of brown tape has been completly removed. If hull still is brown, top layer of tape remains. If hull “looks” pink/white, then top layer is gone and a second layer of epoxy/glass can be added! D’oh !
As I noted above - was very difficult to see which layer of “Brown” tape I was working on, and in a few places I removed the first (plug cover) layer instead of the last glass cover layer.
After a few choice words to/about the dumb builder (me) I managed to get all the external tape layer off and removed the glass top of the float layup from the plug. Inspection indicates it is more than strong enough at 1 layer without needing to add any additional strength or stiffness layers. I may still add the 1/2 oz. glass - but it will be for cosmetic - not structural - reasons.
After removing the top half of the float from the plug, I’ve rubber-banded it in place on top of the bottom half of the float plug to get an idea of how it will mate up. I am still a bit concerned and conservative and may add a 1 inch spacer between the top and bottom halves to add a bit more buoyancy. From the side it just looks too small (height). Once I get a bottom half glassed I will be able to reassess. As shown in the photos, it is held in place by rubber bands, and so far it is better surface than I expected. Will probably only require minor filling and fairing.
The photos explain what I just wrote in easier to see fashion. The glass top for the float was made longer than needed and will be cut back to plug length before assembly. You can see in the photo of stern how much I left for excess. Similar amount at bow. Tomorrow I will take the top half in to work and drop on our mail scales to see what the actual weight is. Bottom half should be just a touch heavier.
A BUILDER’S NOTE: While it seems like a lot of work, and “putzing around”, I find this is the enjoyment of building to a development class set of rules, as it provides intimate knowledge of what has taken place prior to hitting the water. I (personal opinion) find it more satisfying than buying a pre-built or plastic model. Building “CAN” be fun, and it allows you to try new ideas without a lot of cost. I would urge you to give building your own boat a try - whether from available plans - or of your own design. Makes you feel good when asked at the pond and you can reply — " I built it myself".
:zbeer:
OK - weight for the top half of the float was 1 oz. (28.3 gr) - so for the bottom we could double and have 2 oz. (56 gr) - add in the balsa bulkheads, paint, cross-beam connects and fairing and we are maybe looking at 5 oz. (141.7 gr.) maximum per float.
Good luck with your build Dick, I can´t wait to see the first clips of your little Ghost Train pacing along. Today Ernst´s second design of a 65M hit the waters, the owner is Roland who is promoting the RG65 in Thailand.
Look the clips there is no much difference to the large boats with those little ones.
I´m a little bit handicapped after I moved on the first of June - still no internet, I have to go to the internet cafe with the notebook, so I´m slow with responses.
Hi all. Haven’t been around for what must be 5 years. Have been travelling this wonderful country of our’s.
I see that somethings haven’t changed.
Nice to see that there are some new boat’s and idea’s hitting the water all over the world.
Your new little boat is looking good dick.
I haven’t read all the post’s, but am wondering if you have worked out rig sizing etc.
Is this an already “new” class or is this just something that a few of the people that do rather talk got going?
As for my own sailing building activities they are all at a stand still as where I am now living is 350 km from the nearest decent water (where you can sail radio controlled boat’s).
I realise at this point that I have probably posted in the wrong area, sorry.
by for now
Peter Birch
Is the second design available online?
I have the first one downloaded, and the shadows in front of me. I would like to see the second design, or know the changes, if possible, before I begin to build.
Thanks, have downloaded the second plans. main hull looks similar, amas are a fair bit narrower and have a much more rounded deck.
Out of excuses now, better start building.
I havn’t planned it all out, but will probably make a mould for the main hull, and ignore the radiused deck edges, and make a deck mould and a hull mould for the amas. that way it should be easy to knock out 2 boats (so I have one to race against)
The 65M is a recent offshoot of a long (30 years+) established radio class for mono hulls (RG65) that was originally developed in Argentina and which in recent years has enjoyed a growing following in, among others, Europe and the USA. Fortunately, this site has agreed to host the mono hull version and it can be found immediately after the “Footies”.
Of course hulls with flat decks are easier to build, but the mainhull of the
RT65 is 90 mm wide - while the RT65R mainhull is only 78 mm wide.
So there is quite a difference between hull volumes.
Floats:
RT65 - 66 mm wide
RT65R - 58 mm wide
I have given a lot of thoughts and calculations to this cute little trimarans,
before I released them.
Don´t mess it up, just because you try to ignore physical laws.
The right relation between volumes and achieveable boatweights needs to be kept up.
Both little tris should still be ok with 750g,
but of course the lighter the better.
Both prototypes from Sirit had that weight,
despite the slimmer shape of the second one (?).
WIESEL from Germany has achieved 450g ready-to-sail-weight -
using 6mm DEPRON for his hulls!
Re: flat decks:
The hulls/floats/bows can still be submerged in a sudden gust,
no matter how light you build them.
Rounded decks help them to recover,
flat decks prevent that.
So if you would build two completely identical boats of same weight,
but one with round decks and the other one with flat decks,
the “Flatty” will much more often flip over, while the “Roundy” will continue to sail -
no chance for the “Flatty” to win ANY race, as it can´t be sailed to the limits.
But the “Roundy” can.
Just a reminder and I know how easy it is to “hijack” a thread without realizing it as discussion moves along. Posts on this one relative to questions on this specific build are always welcomed, but general topics or discussions specific to other designs really should have their own thread.