I am building the Victor America3 24" and so far assembly is right on, except the instructions for the bulb. Does anyone have suggestions for attaching the shot bulb to the fin more securely? It seems from the instructions that they want you to simply fill the bulb with lead shot and CA and then stuff the fin inside, hope for the best. With my luck, the bulb would fall off in the pond. Has anyone tried a screw or other fastener on the bulb to fin joint? Any help appreciated…
Rock,
While I do not own the A3 24" version, I do own the A3 one meter boat, and it sounds as though construction may be similar–just on a smaller scale.
With the larger A3 boats, you fill the bulb (plastic and hollow) with a lead shot/epoxy mix. This is definately the better way to go–CA wouldn’t be adequate. Be careful to be sure you use a relatively slow-curing epoxy though, otherwise it may melt your bulb. I used West System brand epoxy, but a ‘30-minute’ hobby store epoxy would probably work too. The key to doing it is having everything ready to go, so that once you start pouring the lead and epoxy in, you don’t have to look for anything–that way the epoxy doesn’t start hardening on you while you’re looking for what you need.
Pour a little epoxy, then a little lead, then a little epoxy until you’re done. If it’s like my A3, you stick the fin in once the level of epoxy/lead gets high enough (so that the end of the fin isn’t too far into the bulb, which would make for a very short fin!). Other than substituting the epoxy for CA glue, I think that the kit instructions (though a little hazy–at least the big A3’s instructions were) are pretty much right.
Hope that helped a little.
Andy
Air Capitol Model Sailing Club
www.acmsc.org
How far into the bulb does the fin go? If it is deep enough, you could try drilling some holes through the fin that would then end up completely insode the bulb. This would allow epoxy to flow into those holes and form a mechanical joint rather than just an adhesion joint…
Also, you could try placing the bulb into a shallow tray of water to help keep it cool as the epoxy exotherms. That should help prevent melting…
- Will
Will Gorgen
Have you visited the CupClass web site yet? If not, take a look, as I have posted some time back, a PDF document that shows how I attached my <s>bilb</s> bulb to keel, and also the reinforceing that I added. Take a look, for as Will said - very similar, just a bit bigger bulb !
The one meter A3’s fin has the holes in the fin near the bottom that you’re referring to pre-drilled. If they aren’t pre-drilled in the 24" version, I’m sure they could be very easily.
Dick’s right… visit the Cup Class Yahoo group site…
www.groups.yahoo.com/group/cupclassyacht
Andy
Air Capitol Model Sailing Club
www.acmsc.org
Thanks Andy (and all) for the reply. The fin did have pre drilled holes. The epoxy sounds a whole lot more secure then just mixing lead shot and CA. I will use that method…I will check the link also…Jon
One more question if ya’ll don’t mind. I noticed while painting the mast dowels that they were warped (pretty bad, dip right in the center of each 
). I was thinking of either replacing the supplied dowel with another wood dowel or using an old arrow shaft. Any suggestions? Thanks Jon.
My A3 mast was warped too… I am going to get a carbon fiber mast for it that is the same approximate dimensions. I am also going to forego the sail attachment method shown in the kit instructions and go with loops around the mast to attach the sail (since the mast will now be round).
You can usually obtain carbon fiber from kite stores or online at places like Hang Em’ High Fabrics…
www.ecom.citystar.com/hang-em-high
Good luck with your build!
Andy
Air Capitol Model Sailing Club
www.acmsc.org
Sorry about that dead link… this may work better…
http://ecom.citystar.com/hang-em-high/
Andy
Air Capitol Model Sailing Club
www.acmsc.org
As an alternative to simple loops of string, I have seen some guys that lash short sections of thick walled drinking straws to the back of the mast and then run a luff wire (jackline) through the straws. Not sure what the advantages are of luff wires compared to simple loops, but the system looked really slick and would produce an effect similar to the standard Victor method of attaching the sails…
-Will
Will Gorgen