There are three main areas of preparation – the environment, materials and tooling.

If you want to build a windsurfer, you need a reasonably sized workshop, shed or garage.  The photo shows a view from one end of my workshop.  It’s about 20’ by 6’, which may seem large, but then it does include an oven that is 9’ by 2.5’.  That’s the problem with having an uninsulated workshop at the end of the garden, you need some way of heating it to at least 15C for your epoxy to go off.  In the end I built an oven heated by light bulbs, as I started to use epoxy that needs a post-cure at 50C.

I’d think twice before using a room in the house for this type of work – some of the materials are hazardous, especially fibreglass/epoxy dust.  I keep children and animals out the workshop (and think twice before letting my windsurfing buddies in).

The workshop has to have electricity for the vacuum pump, and decent lighting for you to see low and high spots when you are shaping that board!  I even went so far as to cut skylights into my roof (£5 worth of Perspex from B&Q, bargain) to get daylight on the job.

One final thought on the board building environment.  As you build a board, you spend an awful lot of time thinking – its better to spend 5 minutes thinking than 5 hours correcting.  You need a place that facilitates quiet thought.  I highly recommend a CD player and some Bob Marley.  My friend Nic goes one step further, he has a TV in his workshop, but then it always takes him years to get a job done so maybe that isn’t a good thing.

2.2         Materials

The core of a composite windsurfer is made out of Expanded Polystyrene.  This is the white material that you find in all sort of packaging, and also that insulates lofts etc.  You can by it from B&Q in sheets, but what we are after here is a big old block of the stuff, preferably 8’x4’x2’.  Blocks of this size are easier to get hold of than you’d think – look under insulation supplies in your yellow pages.  There are two important factors when selecting a grade of EPS, density and beading.  Density is straight forward, we are looking for 11kg/m2.  Lots of places do 16kg/m3, but spend the time to find 11/12 kg/m3.  I found one place near Bristol that did 8kg/m3, but the foam was not strong enough to withstand any sort of vacuum pressure.  1lkg/m3 is what we are after.  The other factor we want is close, small beading.  Beading refers to the beads of polystyrene, they need to be small and even.  Gaps in the structure are no good and lead to problems.  One final point about your block of foam – don’t be surprised if the block is not square on every corner.  When I take delivery of a block, I always spend a little time with a large set square, checking each corner.

The other type of foam used in the composite laminate is High Density (HD) foam.  There are two brands of foam that are associated with windsurf production, Divinycell and Airex.  Divinycell has a construction that is extremely strong, but does not bend around corners easily.  Airex, given appropriate relief darts, will take sharp compound curves such as those found at the back and front of a board.  Airex is the high density foam of choice for ECB.  Airex comes in 8’x4’ sheets that vary in thickness and density.  For board building, my recommendation would be to use Airex 63.80 (80kg/m3), in a thickness of either 2mm or 3mm – 3mm for wave boards, 2mm for larger freeride boards.  The great thing about Airex is that it sands really nicely too, an ideal material for our purposes.

In terms of supplier, I used to get my EPS from Combat Polystyrene (which I think has now been merged with another supplier).  It’s best to try the yellow pages for EPS anyway, as shipping a 8x4x2 block half way round the country could be pricey.  For high density Foam, I use IMPAG UK Ltd, based in Gloucester.  IMPAG is a small firm, but really friendly and reliable.

Fibreglass (or reinforcement, or glass) is the basis for the outer hard skin on the board.  When you buy fibreglass, is comes on rolls of varying width, very much like you would buy cloth from a haberdashery (not that I’ve ever been in a haberdashery).  It comes in many different forms and weights.  There are two weights of cloth that get used in windsurfers – 6oz/m2 (200g/m2) and 4oz/m2 (140g/m2).  There are two types of cloth used – carbon and S-type glass.  You can use more exotic materials such as Kevlar or hybrid cloth, but to be honest I question the value of these expensive clothes to the amateur builder, especially if you don’t have the facilities for a high temperature post-cure.  The three types of cloth that I use exclusively now are; 6oz S-type glass, 4oz S-type glass and 6oz carbon fibre.  I’ve used these in everything from wave boards to speed boards to intermediate freeride boards.

The frustrating thing with fibreglass is that in the UK it is ridiculously expensive to buy as a retail customer.   Sad though it is, I find it cheaper to buy fibreglass in the US and ship it to the UK.  Even accounting for the import taxes and shipping costs, it is still cheaper – isn’t that awful?  I’d love to use a UK company for glass, but instead use http://www.fiberglasssupply.com/.  They do every cloth, and have great service.

Epoxy resin is a two pack formulated product that is used in conjunction with fibreglass.  ‘Two pack’ means that it comes in a box that has, er, two packs (or pots) in it, the resin and the hardener.  When epoxy is mixed together in the appropriate volumes, and spread over fibreglass, after a period of cure the fibreglass becomes extremely strong, both in terms of impact resistance and lateral strength.  Epoxy deserves to be handled with caution.  I always wear long sleeved shirts, latex disposable gloves and a mask when mixing and spreading epoxy.  Follow the manufacturers safety guidelines to the letter.

It is not economical to ship in epoxy from the US as it weighs too much.  I buy epoxy in the UK (wish my French and German was better) from SP Systems, via one of their distributors.  I’ve used SP115 for a long time, it comes in 13.5kg barrels at £180 (enough for 4 boards if you are careful) or 5kg packs at £85ish for the more cautious investor.  The forgiving properties of SP115 (long time to gel, reasonable mechanical properties) make it easy to use.  I’ve started to use the Ampreg range now, which I also recommend.  Its more expensive, but has better mechanical properties if you cure properly.  One thing I will say about SP is that whilst their products are expensive, their customer service and website are both superb.  Their guys make time to help, and their website has comprehensive properties for all their products.

‘Inserts’ is the collective name for anything that is plugged into the board, i.e., the mast box, fin box, footstrap inserts and vent.  All of these are available from http://www.fiberglasssupply.com/, with a myriad of different types – take your pick.  One recommendation that I would make is the Northwest 3-post footstrap inserts.  They are brass threaded inserts that are filled with a gel to stop you messing up the thread with epoxy.  They come with a stainless screw and washer too.  Bargain.

2.3.1.1           The Router

It may well be possible to build a board without a router, but it would be hard work.   In order to install the mast box, fin box and footstrap inserts, you need to be able to create box shaped holes in the board.  The router is the optimal tool to do this.  If you are buying a router for board building only, my advice would be to get the cheapest possible (I reckon about £25), with a straight flute ¼” bit.

In the picture here, you can see my router ready to rout a mast box stringer in a repair area.  What you can’t see is the safety gear I’m wearing.  The router throws shards of fibreglass everywhere, and creates lots of airborne fibreglass dust that is extremely dangerous.  I wear a disposable overall, kitchen gloves, ear protectors, a full mask and goggles.  It may seem like overkill, but once you experience the itch of fibreglass dust on your arm, and consider what a lungful would do….

2.3.1.2           The Sander

These days I don’t really use an electric sander very much in the board building process, although it can be useful to have one around occasionally.  If you do get an electric sander, make sure you get one that takes sheets of paper that can be cut from a roll, otherwise you end up paying through teeth for sandpaper that is backed by Velcro hooks.

What I do use is a 10” sanding block from B&Q.  It has clamps on either end and is perfect for the job in hand.  I also have a small 4” cork sanding block that has also seen good service.

2.3.2        Bespoke and Specialist Tools

These you will not find in B&Q, and most likely have to make yourself.  Who said this was going to be easy?

2.3.2.1           The Board Stand

I built my board stand from the plans in ‘Maui Boardbuilding and Repair’ by Bill Walters (only $9.82 from http://www.fiberglasssupply.com). One thing I would say is that is worth taking the time to really pad the four corners of the stand.  If you don’t you’ll find that you keep getting dings in your board as you go through the build, meaning you use unnecessary filler. I use an old bath towel divided into four, and replace the padding for each new board as it gets covered in epoxy.

The greatest property of EPS for the budding board builder is that it can be cut in great slabs using a hot wire cutter.  A hot wire goes through EPS like a knife through butter.  The are two main parts to a hot wire cutter, the frame to hold the and tension the wire, and a box to generate current through the wire (so heating it up).  Now I’m in a lucky position here.  My friend Nic considers himself a bit useful with electronics, and also needs his boards repairs periodically (I’d love to say this was through learning to loop or something cool like that, but its more due to him having shagged kit).  So Nic built me a one-off hot wire cutter with variable current that has served well for 4 years, and not set the workshop on fire yet.  If you don’t have a Nic equivalent, all is not lost.  There are lots of sites on the internet for hot wire cutters,  especially if you remember that the model aeroplane community use hot wires to cut wings.  I’d be tempted to connect a wire direct to a 12V car battery, but I haven’t tried that so don’t take my word.

In terms of the frames for the wire, I have two.  The first is an ‘H’ frame that has a wire spanning the bottom and a piece of appropriately tensioned bungee on the top.  One side of the H is hinged.  It also worth building this in such a way as to make the wire variable length – note the holes in the left side of the central member.  This frame is used to make long flat cuts for the rocker and deck.  Its also useful for splitting the 8’x4’x2’ block of foam into more manageable chunks.

The second frame I have is for shaping the board.  The wire in this cutter has a variable angle of attack.  The use of this frame becomes clearer in subsequent sections.

Crocodile clips are used to connect the power source to the wire.  The wire I use is Constantin wire from Maplins.  This is constant resistance wire, no idea why this is a good thing but it was Nic’s recommendation.

 

Now my workshop is at the end of my garden, and in the winter it gets really quite cold.  The problem with this is that the epoxies need a temperature of above 15C to cure at all.  Also, some of the better epoxies benefit from a post cure.  This means that they set optimally if you cure at 21C for 24 hours, following by 50C for 12 hours, for example.  I guess you could get a couple of massive heaters in the workshop, but a more cost efficient way of dealing with this problem is to build an oven.

My oven consists of a 9’ by 2.5’ plywood box, lined by 1.5” polystyrene (the time invested in the hot wire cutter is paying dividends already!).  The heat in the box is provided through two banks of 5 100W lightbulbs.  I only use the oven for curing at relatively low temperatures, so am happy using light bulbs controlled with a quality thermostat as a heating element. Consideration should be given to the safety hazard of using light bulbs. The thermostat for the oven came in kit form from Maplins.  Again, Nic built my thermostat with a range of 0-70C, and hysteresis of +/- 2C.

2.3.2.4           The Vacuum Pump

The vacuum pump is an essential piece of kit for the composite board builder.  The use of a vacuum pump allows substantial but even pressure to be applied to all parts of the board when laminating.  What is not so easy to find in the UK is a supplier of vacuum pumps that are not 3-phase industrial strength monsters.  I got my pump from http://www.rietschle.co.uk/, the model I choose was the VTE6.  In operation, this pump takes 6m3 from the bag per hour, and applies easily enough pressure.  It cost about £300.  In retrospect I think I would have bought the VTE3, which would do the job fine and is substantially cheaper.  That said, its good to get up to vacuum pressure quickly, especially for the top layer of HD foam, so maybe the additional cost is justified, it’s a close run thing.

As well as a vacuum pump, you need a number of sundries.  The pump is connected to the bag via a length of special non-collapsible tube, about 2m in length.  To connect the tube to the bag, you need a non-return valve.  This valve bridges the bag.  A second non-return valve is used to connect a vacuum gauge to the bag.  If you are going to spend you money anywhere, get a decent vacuum gauge – too much pressure will write-off your board at any point in the process. 

I see on the Internet that several people have successfully made a vacuum pump from the compressors on discarded refrigerators.   This may be a cheap alternative, but bear in mind that the pump has to run for 16 hours continuously – is a modified fridge pump up to the job? 

One of the problems with placing your board under vacuum pressure is that you need a mould to stop it distorting out of shape.  You can see in the photo that I’ve used the foam offcut from the hull as a mould, but if you look carefully, you’ll see that underneath that is a platform made from 1” plywood mounted on 2”x4” battens.  This platform stops the foam mould from distorting.  The platform is 9’ by 2’, as I tend to build boards that are less than 9’ long, and less that 2’ wide.  You could increase the dimensions to cater for bigger boards.

2.3.2.5           The Callipers

If you are taking dimensions of an existing board, you need a pair of large callipers to measure the thickness of the board at 15cm intervals.  Here are mine, witness the quality.

2.3.3        Consumables

By consumables, we mean any material that does not end up in the board, but has a role to play in building the board.

There are companies in the UK who are dedicated to supplying vacuum consumables.  Our needs are relatively simple.  We require;

-          Peel ply.  This is a cloth that is placed directly onto the laminate.  Once the laminate has cured, you can peel off this layer, hence its name

-          Release film.  This covers the peel ply and stops the epoxy from bonding everything to everything.

-          Breather fabric.  This is a woolly type of cloth that allows the vacuum pressure to reach all parts of the board.  Without a breather fabric, there would be high and low points in vacuum pressure resulting  in a poor bonding in the laminate.

-          Bag material.  The vacuum bag is made from polythene.  It is bought in weight by the pound, don’t ask me why.  I get a width of 1.5m.  This material is also useful for masking large areas.

-          Vacuum tape.  To make a vacuum bag, you need to seal the edges.  This is done with vacuum tape, which is a squidgy double sided tape.

I get my vacuum consumables from Aerovac – good service, relatively cheap.  For small quantities, I use a local distributor of SP products.

 

The board building process uses lots of small batches of epoxy, filler and paint.   It can get very expensive to use all the mixing paraphernalia found in chandlers, so here is my guide to the cheapskates world of mixing.

First of all, you need a pot to mix in.  You shouldn’t use any form of plastic to mix, as it is possible that the plastic will react with the solvents in the paint, etc.  I find that the paper cups used in the coffee bar at work are ideal for most purposes.  They are reasonably large, inert, and the ladies behind the counter don’t give a toss if you take a load.  While you are there, take a bunch of the wooden stirring sticks that are used for stirring sugar into tea.  These are just the ticket for the workshop and save 10p a time compared to the mixing sticks in the chandlers!

When using epoxy and two pack paints in small quantities, it is important to get the ratio of resin to hardener correct.  There are two ways to do this.  For epoxy, you can buy the dispensing pumps that come with smaller packs.  These cost £10 or so, but are value for money given the amount of time they save.  My preferred method is to use syringes.  The problem here is that a chandler will charge you £2.50 per syringe, which is extortionate.  I’m fortunate, as there is a nurse that lives just around the corner.  Her Fanatic Snake has been in for a couple of repairs, and she has paid in syringes.  Cushtie. If you do get hold of a pair of decent syringes, take the time to clean them thoroughly with an appropriate solvent, and then dry them or the solvent will attack the plastic rendering the tool useless.

In my workshop, I have two grades of drafting tape – really cheap stuff from B&Q, and really expensive gear from 3M.  If you are using tape to hold something in place, it is pointless to use something that is £2.50 a roll.  You are better off using the 30p B&Q tape.  On the other hand, if you want to put a barrier to epoxy in place, you want a high quality drafting tape.  Its worth the investment.

There are times in the laminating process where it is useful to have a couple of cheap brushes to hand. B&Q do packs of brushes at 99p, quality is not an issue here so these are ideal.

I get all my sandpaper from Screwfix.  They sell it in economical rolls for 10m.  I seem to get through a lot of 40/60 grit paper, but also 120 and 240 grit when keying for paint.  You also need sheets of wet and dry paper, I use 240, 300, 400, 600, 800, 1000 and 1200 for a final finish.  It sounds like a lot of paper, but you only need a sheet of each.

I’ve just read this back and realised I sound extremely tight, but hey, what’s the point in being ripped off?