Hi Dick,
as you said , the wire is just the S/S rigging wire for 25Kg.
As you said, the the power source is adjusted to avoid too hot wire that may also shorten the life.
Next, will be similar to your carving tool, expecially when is wanted an unsinkable boat ! I shall find this type of solder Iron
Hope that many readers could find these treads an interesting topic .
Now I need to reprocure the Foam, the orange type is better for sanding.
I decided to make a Columbia 1958, 125cm long - scale 1/17
Several drawings on my desk, the last I choose is the American Eagle of 1964 because of the realative long keel compared with others.
It may presents some additional wet surface, but it may also offer a better close hauled . I like it !
The frames are not cross checked yet, waiting to draw the scaled 1:1. The lenght is not the definite one but it should stay in the order of 120cm.
I decided for the American Eagle and started to cut the foam blocs with my new tooling.
Definitevely a clean job !
The “waves” , visibiles in the 3rd image , are due to lower current applied to the HoT Wire
Way back in my sailboard building days, I used EPS foam for some boards. To get a nice uniform cut over 9 feet, I used two templates that were screwed to the side of a single block of foam. The hot wire could then be rested on each template as it was slowly pulled through the foam. There is more foam waste, but a very smooth rocker line with no chance of twist. The width of the bow was over 2 feet, so there was a lot of fiddling with voltage/current to get the wire to cut smoothly!
I might try building your J-class boat with this technique. I’ve never tried it before, and that is what is on the bench next, after I finish the Rg-65 “blue splash” and a star 45. Too many projects… and claudio keeps adding to them!
Thanks claudio, for making all your projects so accessible to anyone with internet. Your efforts are surely spreading rc sailing around the world!
Hi,
pleased to know ! I suppose you are talking about the Enterprise 1930 !
this is my first motivation, render free of charge the basic material that are the plans and associate drawings.
Some time I add also some building construction indications as experimented by myself.
It is also for me the first time with this Hull shape and from the first attemp is not easy for sanding .
Here some progress. I need to make some round sanding tool !
Not easy job !
Smooth and linear hull shape are more adapted to this construction method.
I found the most difficult part during gross sanding being the gardbord strake (retour de galebord)
Anyhow I’m close to the end finally and not ready to start up again !!
With this experience I think that a normal hull like IOM, AC100/120, Class M , RG65 , etc are more simple and fast making for this foam tecnique.
Yes, I shape a “classe B” (like a RG65 but littlz different) with this method and it’s more simple. The Twelve with winged keel are more simple at the galbord but they have a bustle…
I start my next boat, a personal plan like a 90 footer (america’s cup ~1885 - 1903). It’s the same difficulty…
Great job as usual Claudio did you manage to find an easy way of sanding those smooth curves in the mould that you have ? or is the result lots of elbow grease & a good eye :cyclops:
I’ve never tried carving/sanding foam blocks before but I would’ve thought that any filler would be much harder than the foam, thus creating difficulties if the filler needed any sanding. Would it not make more sense to glass the foam first and then apply filler?
If careful, you can fill/fair using wall board joint compound - apply in very light coats. It sands “slightly” easier than the extruded foam. If you plan to use plastic packing tape for glass release, a very fine finish isn’t required. Just need to fill any deep hollows or low spots cause by accidental “bumps” that appeared while handling during the shaping phase. Keep in mind, if using 4 oz. glass cloth (example) it will easily cover and hide most slight hollows. You still have to work the foam high spots down though.
Hi Dick,
the defects are deep hollows and the direct coverage with glass I think will not making them disappear. Certainly I can always intervene after as suggested by Row and as I did it on previous model.
I also used the packing tape and while the big hollow are almost become very small, the surface is not what I would like.
Let me try and I will report back, meanwhile here are the defects occurred during sanding with a sort of chipping rolling under the abrasive.
I’ve had “tear-out”/Gouges when sanding myself. When I switched to a finer grit sandpaper it seemed to go away. I usually use 80 grit paper (here in U.S. it is often used for sanding/refinishing wood floors) and once I get down to the basic shape I move to about a 150 grit paper. I do not know how this translates into the paper “grades” that you see/buy over there. The 80 grit stuff here is very coarse, black and usually comes on a circular disk. The 150 stuff can be gree/white or tan over here. Usually in small copy paper sized sheets.
If you would like to try some, I can mail you some samples to compare to your paper “grades” - just let me know. PM me your address please if you want to try.
Dick,
very kind of you, we have here in France the same grid type. The one I used was also 80 grid but the chippng was created too. With 120 the problem do not occur so far, but I will spend a life to get the wanted shape.
Strange , but I have observed that not all the foam blocs behave in the same way, like there is a sense/direction of the structure.
For instance the same bloc producing a chipping in one sanding direction , is not doig it in the orthogonal direction.
I should ask the manufacturer about this subject.
Anyhow the decision is taken, the repair will come later if necessary.
Cheers
Claudio
Quand j’ai terminé de poncer (at the end of sanding?), j’ai mis une couche de tissu de verre de 49g/m2 + epoxy. Ensuite poncage de finition et polissage.
C’est un petit peu plus long mais plus lisse qu’avec de scotch.
did you manage to find an easy way of sanding those smooth curves in the mould that you have ? or is the result lots of elbow grease & a good eye :cyclops: