Monday 31 March 2014

Recovering Mattresses

Part of the refurbishment of the boat is to recover the foam mattresses. They are currently covered in vinyl, which I don't think is appropriate for the mattresses. It clearly works for the seat cushion pads as it is cleanable and they are likely to need something which can be wiped down but it would be somewhat uncomfortable as a sleeping surface.... especially if we actually have a summer!

I decided to recover the mattresses in a navy and off white striped ticking. It is hard wearing and 100% cotton. Whilst it won't be easy to remove from the foam mattresses, they are at least washable and there is always the option to explore whether it is possible to have the mattresses dry cleaned with the covers on.

Initially, I though about unpicking the original covers and using those as a pattern but looking at them, I don't think they were all that well made to start with. So I, started from scratch and used the foam mattress to re-create a pattern. I am pleased I decided on this route  because the finished product looks rather good even if I do say so myself! I only have 3 more to do.... groan....

Saturday 29 March 2014

Sewing the Vinyl Headlining

Vinyl is not the easiest material in the world to sew, as I discovered. The initial scrap I test sewed was fine as a single layer but as soon as I tried to sew 2 layers of the vinyl, my machine ran into trouble. The foot seemed to be sticking and the stitches became really uneven. I changed the stitch size to the maximum size and loosened the tension. Neither approach did any good. I then switched to the heaviest duty needle I could find. Unfortunately, that didn't help much either.

The fact that it sewed one layer of vinyl perfectly and not 2, suggested to me that the bottom layer of fabric was not moving at the same pace as the top layer, so, I ordered a Teflon foot for my machine along with a walking foot. In addition, I ordered some leather needles, as the vinyl I am sewing is quite similar to leather in terms of weight and texture.


Walking Dog Foot & White Teflon Foot

The purpose of the Teflon foot is to allow the fabric to slide along the foot without sticking. I tested it out when it arrived and whilst it did work on scraps, I worried about how it would cope with large panels of the vinyl as they are going to create far more drag and resistance to the machine.

The walking foot is a really interesting attachment for a sewing machine. Basically, the foot has its own feed dog, which moves the top layer of fabric you are sewing along at the same pace that the bottom layer of fabric moves at. When you connect the foot to the machine, you position the walking foot lever over the screw to tighten the needle. This allows the feed dog of the foot to move at the same pace as the feed dog on the sewing machine. 


I tested the foot on a scrap and felt that the walking foot in combination with the leather needle is definitely the best way to sew the vinyl headlining. I found the largest Leather needle (size 100) to be the most appropriate for the weight of vinyl being sewed. 

Test strip

The Real Sewing Begins

Once I had tested that I was not going to completely mess up the headlining, I started sewing the smaller more fiddly bits. I rationalised that at least if I make a mess of one of them, that I have enough headlining left over to cut a new piece if needed. 

I started with one of the curved pattern pieces. The thing you have to remember with vinyl is that it is that much harder to maintain a smooth curve because of the weight of the fabric and as it doesn't  lend itself to being eased into curves like a thinner woven fabric would. The best way to deal with curves is by cutting out small notches, which allow the vinyl to have a bit more flexibility when working round awkward concave or convex shapes.

Sewing curves on vinyl
Whilst, I have not yet finished sewing the headlining, I have made good progress. I have finished all the fiddly strips and I have finished sewing one of the large panels. I doubt it will take me more than a few hours to finish the last few large panels.


Thread

The thread I used for the sewing of the vinyl headlining, is a thread called Nylbond. It is a close bonded nylon yarn, which makes it particularly strong. Also, being nylon it is better suited to dealing with damp, UV & mould.

Monday 24 March 2014

Traffic Jam in the Countryside

First off, this post has absolutely nothing to do with the boat but I thought I would post it up as it is a little bit of fun. 

I was returning home from baby sitting a good friend's twins. My friend was suffering from toothache and had asked me to babysit, whilst she went off to the dentist. I had just turned out of the lane she lived down when I encountered a tractor with a link box on the back and a herd of sheep in the front. It's a good thing I was not in a rush to get anywhere because it took ages to get to the main road but, it was fun.

Notice the twin lambs in the link box with the ewe

Monday 17 March 2014

How Much Carpet Do I Really Need?

The good news is that with some careful placement of the carpet templates, I have been able to reduce the amount of sisal carpet needed. I have also eliminated some sections, which I feel would result in carpeting overload. I see absolutely no practical or aesthetic reason for having carpeting on a shelf! This really helps as it removes the awkward templates that take up a lot of space and result in an enormous amount of wastage. This is of course good news for the bank account.

I think the postman might have thought I was a wee bit mad, as I had to use the paved area outside the house to lay out all the carpet pieces from the boat. It looked like some sort of bizarre jig-saw puzzle.




Monday 10 March 2014

Cutting out the Vinyl Headlining

Although, I don't enjoy being ill, I was rather grateful to use it as an excuse for not helping John to rip out the old headlining with its disintegrating foam and the carpeting. Being ill has it's advantages! Poor old Genesis looks quite bare without her headlining.... even if it was saggy.

Being ill has not gotten me out me out of having to trace all the headlining shapes and then having to add on a seam allowance. A tedious job at best. It doesn't help that there are no straight lines to make it quicker! Make certain you have enough pattern paper BEFORE you start!


Once all the patterns were completed, they were cut out on the floor of our lounge in one session. The best route was to lay out all the pattern pieces for the headlining out in one go, as I wanted to have as little wastage as possible. I wasn't able to use needles for the pattern pieces, as they leave holes in the headlining, so I used sticky tape, to stick the paper pattern pieces to the vinyl headlining. Not ideal at all. By the time I had finished cutting out the pattern pieces, my knees were positively covered in bruises.

Headlining Patterns being arranged and cut out


Pattern piece stuck down with sellotape

The trickiest sections to cut out were the smaller bits. I ended up using a sharp stanley knife in combination with the sellotape as using a pair of scissors caused the pattern pieces to move too much.

Sunday 9 March 2014

Minefield?

One of the essential upgrades for Genesis was to install a second battery to handle the domestic loads like instruments, lights etc. My thinking was to avoid using the engine starter battery for anything other than starting the engine. That way we would not have to worry about a flat battery from leaving something on. Also on the wish list was some sort of "battery gauge" to show how much juice was left and when to start charging.

I naively thought this would be a quick and easy project but it turned out to be a bit of a minefield, the more I learned about battery types, split charging, battery monitors etc. It has been a bit of a journey, and I think I've learned a bit along the way. I don't profess to be a battery guru, but I certainly know more than when I started. Hopefully my experience will help others with questions about this topic.

The choice of battery type should have been simple enough. With my rudimentary knowledge of batteries, I knew I wanted a deep-cycle battery as big as I could fit under the bunk in the rear cabin. For the uninitiated, deep cycle batteries are designed to deliver power more slowly over longer periods than the typical starter battery, which delivers a short high burst of power. Deep cycle batteries tend to have thicker plates and can recover from deep discharging more frequently. Deep cycle batteries come in several different types: wet-cell, Gel type  and AGM. The Gel-type and AGM batteries appear to be better at deep cycling than wet-cell batteries, and I initially thought I'd go for one of these, but they require different charging voltages (and cost a lot more!). This is where it started to get more complicated than I expected!

Most modern chargers have different settings for the different types of battery, but what would happen if you try to charge different battery types off the same charger at the same time? You run the risk of overcharging (and damaging) one of the batteries because of the different charging voltages.

I researched as much as I could on the Internet, but could not get to a satisfactory solution. Some sites suggest using 2-stage chargers rather than 3. In the end I was not left feeling comfortable about the various ideas so opted to keep the battery type the same as the engine starter battery (wet cell); this way the charging voltages would be the same.

The next challenge was to figure out how to charge both batteries off both the alternator and the shore-powered charger whilst keeping the circuits separate. In simple terms, the battery circuits need to be isolated when in use (to avoid discharging the starter battery), but connected when being charged (from either charging source).

The great thing about the Internet is that someone has always done it before; I started to learn about the concept of split-charging.

There is a simple way to achieve split charging i.e. you could use manual switches, but you need to remember to connect the battery circuits when charging and remember to disconnect them when charging is complete. Forget do do so and you could well end up with a flat engine battery when you least need it. As we view ourselves as "gin-and-tonic" kind of sailors, this would be a recipe for disaster!

There are a number of solutions commonly used and I'll try and explain these as best I can:


Split charging diodes


A diode is a kind of one-way valve for electricity. Electricity only flows one way through the diode. If you connect a diode between the batteries and the charging sources, then in theory you can charge both batteries simultaneously and still keep the circuits separate. Sounds straightforward, but diodes cause fair voltage drop across their terminals and it increases with current flow. Depending on the diode, this voltage drop can be between 0.7V and more than 1V. It doesn't sound like a lot, but in battery charging terms, this is quite significant.
 with a 12V battery. This means that the batteries don't see the required voltage, charge slower and may not fully charge.



Split charging relays



These are electrically operated switches that will connect/disconnect the charging sources (alternator or shore-fed charger) from the batteries depending on whether they are running or not. This solution needs 2 relays  - one powered by a contact on the alternator and one powered by the shore supply.

The relay option seemed to be the best although more complicated in terms of wiring.



Battery gauges/monitors



Around this stage I 'd been researching battery monitors as I wanted a way to estimate how depleted the domestic battery was so that it could be recharged when appropriate. I was hoping that something fairly simple like a voltmeter would do the trick. Wrong again! 


Battery Capacity
State of Charge versus Voltage

This chart shows the battery state of charge for a given voltage. As you can see, a fully charged 12V battery actually has a voltage of around 12.7V. When the battery is around 50% discharged it has a voltage of approx. 12.2V. For most lead acid batteries, discharging the battery below a 60% state of charge is apparently not good for the longevity of the battery, thus using a simple voltmeter is not going to be a good idea. A further complication is that the battery "ages", for lack of a better description. In other words, it's capacity reduces with each successive discharge.

There seem to be 2 main types of battery monitor - those that count the Amp hours used, a bit like a domestic electricity meter and then estimate the charge remaining and a second type, that uses some clever electronics and algorithms to build a history of the battery from it's charging/discharging profile and estimates the capacity from this.

I must admit to falling for the sales pitch and going for option 2! I opted for a Smartbank/Smartgauge  combination. This is a combined battery monitor and split charging system with some clever electronics thrown in to manage the whole lot. The beauty of the system is that it costs marginally more than a split-charging relay set-up with a separate battery monitor, but has simpler wiring, only one relay and has some nice-to-have features like being able to use the domestic battery to start the engine in an emergency. It also has contacts to allow you to trigger an alarm to warn of low battery state. 

Sounds like the fit-and-forget type of kit that a "gin & tonic sailor" needs!

Here is a photo of the key components: this shows the control box or "Smartbank", the rather heavy duty relay and the battery monitor or "Smartgauge"