Sunday, 26 February 2012

Bimini vs arch for solar.

The offending stays!
Well I had hoped this would be an easy decision, but to be honest I think the boat has decided for me. After careful examination of the  transom and much head scratching, I will have to go down the bimini route.

The boom on our boat is longer than most, stretching right back to the sugar scoop on the transom, the back stays chain plates are low down on the sugar scoop. there is no way I can get an arch on without having the mast stepped (ie removed), this would be a fairly expensive option. The only other ways would be to have the arch welded around the stays , the welding would need to be done on the boat, or have the arch made in two sections then assemble on board, neither of which I fancy.

I have checked for access and I believe I can deal with the sail cover and reefs with the bimini up ,as if I go ahead with the bimini install it is going to be permanently erected.  I am trying to figure out if I can do a part permanent bimini , ie reinforce the rear section while still allowing the forward section to be folded back somewhat, which allows far better access to the boom, why is everything on a boat so complicated?

I think I will take her out with the bimini up and try to uncover the sail and reef it without dropping the bimini before I go ahead a buy any gear for the bimini mounting frame, time is ticking away , we are still hoping to drop those dock lines for the last time late April

The chain plates on the sugar scoop

The backstays going right through the middle of where an arch would be!

For the non boaties, a Bimini is a kind of folding sun shade with metal poles and canvas which folds out over the back of the back , Stays are normally metal rope which attaches to various parts of the boat holding the mast up. Chain plates are the metal plates which are attached to the boat - front middle and rear and the wires that support the mast are attached to them.

Thursday, 23 February 2012

Solar Power on a yacht

Mounting the solar panels is the next job on the list, I managed to get a very non marine quote for an arch from a local engineering company, the first guy i called quoted 2-3000 pounds, now for what amounts to a couple of hundred pounds of metal, and really a days work, I thought this a tad expensive. The local machine shop was 650 pounds including tax, same arch!

I'm not yet set on an arch, for several reasons,  a large piece on inertia hanging off the transom is not the best thing in the world to have on a boat, you also have to consider the possibly of breaking waves on the rear as well, more weight at either end increase pitching.

I priced up doing a bimini install, and it was almost as expensive as the arch, but at least that way I don't have a big ugly arch hanging off the stern and the weight is more central, the drawbacks are partial shading from the boom when underway and the boom itself. The boat does not have a rigid boom vang, so it is supported solely by the topping lift (ie a rope) and should it chafe the, boom will come crashing down on all those panels (granted they may be a life saver in such a situation, better them taking the brunt than someones head!

I have bought 400w of solar panels- 5x80w units from a company in germany, no doubt cheap chinese stuff but they have TUV approval and tempered glass. Watch out when looking at cheaper solar panels, some go bad after a few years due to the coatings they use misting up, or the cheaper glass going opaque and milky.

I got a TUV approved MPPT controller, it's actually quite a good piece of kit and the charger does equalisation of the batteries and a few other nifty features, it also has a remote display which has a data logger for the geeky ones among us, you can put in an sdcard then read it on a pc . This shows power and other data over the last month of use.

The MPPT controllers supposedly gain around 10% extra charging due to less power waste, combined with the new agm batteries (AGMS also waste less energy during charging than normal lead acid) I should gain a good 20% extra over lead acids and standard solar controller and not at much extra cost.

I need to toss the coin fairly soon over the mounting technique I am going to use as the departure date looms ever closer!

Tuesday, 7 February 2012

Wind instruments

Now the boat being an ex charter was a bit bare on the wind instrument department, having a simple wind vane and not much else!

This I could almost live with, but since the most likely install of the solar panels will be on the bimini , it is going to blot out any direct view to the wind vane. To resolve this issue I bought an electronic wind instrument, a nasa marine clipper wind gauge and anemometer with digital display.

The nasa is a lower end wind instrument system, though works just fine, the problem came when trying to fit it, could we get the cable down the mast without it fouling on something?  I have no idea how the experts do this task, but I am getting to the stage where I may just buy a wireless system, It is looking more and more likely that the mast will have to be removed to fit the cable, this is one big expense.

The negative part is I jumped the gun and cut in the display on the table side, normally this would not be much of a problem, most manufacturers make roughly the same size square displays, but not the nasa clipper , theirs is rectangular, this is going to leave me with a rather odd sized  hole to fill.

So heed my lesson and I should have known better, don't go cutting holes till you have an up n working tested system. I was conned by the small inspection plate at the bottom of the mast, which allows me to see inside the mast which looked as if it had plenty of room, at the top of the mast however it was a different story, no access at all and after drilling a couple of holes and getting no where feeding the cable down, I did not want to pin cushion an important structural part of the boat.

The last option we have is to use the mast head anchor light cable , pull it out trailing a messenger line up the mast, then use the messenger line to pull the wind instrument cable and original anchor light cable back up, it is a kind of risky tactic as being as tight as it is, I might end up being unable to get the anchor light cable back up.

Update, I ended up fitting a tack tick mn30 wireless unit, luckily it filled the hole I made ok!

Wind attempt number 1

Powered up and running!

Wireless tack tick unit  finally fitted and working!

 Need to replace that 12v socket and redo the gelcoat around it!