Thursday, June 27, 2019

New projects on the go. Time to experiment with some new materials and ideas.

I have started a new project with some totally recycled EPS from Polystyrene Solutions who are a local Gold Coast company not 2 km from my home. They produce EPS from beads as usual and make them into large blocks. From this they hot wire cut their 1lb foam into blocks to be used in pontoons for marinas. The offcuts are then placed back in the process with virgin beads and with heat / steam this fuses the off cut blocks back together to form a large block again. So totally recycled without leaving the building. To date I believe they are the only people doing this anywhere. So the guys hot wired me some blanks and I had Fitzy from Elite Cutting in Tweed cnc them into a couple of 5ft10" and a 5ft 4" Hydro V fishes. Now to say they are light is an understatement, The 3mm Paulownia stringers I glued them up with are heavy by comparison.
 Check out how much the glue expands through the EPS beads when gluing up the blank

 Now, because the blank is only 1lb EPS I need to cut in some heavier foam to seat the fin boxes in or they will just bust out if impacted. So I have to measure out the fin placement.

And glue them in.

 Then trim them up and foil it flush to the blank.
 As usual, scribe and trim off the rail

 Mark out and cut 4mm rail bands on the band saw.
 The blue blank is EPS or Extruded Polystyrene which is totally opposite to the other 3. It is hard and heavy as it is dense.It will dent and not bounce back like EPS. So it will be in the mix as well.

First rail band on. Now this is important as the foam is so light that when I bag the skins on it will come down onto the rail band and not squash the foam. This way the blank is encapsulated in wood.
And because the blank is so light I am going to use 2mm skins so as to not have to apply too much pressure on the foam while vacuum bagging. I will do 2 layers of 2mm. So as to laminate a strong shell around the soft foam. Basically using the foam as a mould this time.Anyway that is the plan at this stage.

Rail bands on each rail and using the hand plane to foil the rail band to the top and bottom.
 I have a plywood top table that I made to be able to screw the pieces of wood onto where I need them to hold the rocker in the boards as they are bagged.Without the blocks the pressure would flatten out the rocker. So it is a simple matter of giving each end support. It is not necessary to have blocks every 100mm like I see some people do. You can spend more time building the rocker table for each board as it takes to build the board. Keep it simple and do what you need to. Don't over think and over engineer it.
Because these boards have a V in the tail I cut the same V in a piece of Paulownia and gun stable it to the block of wood for support. Also the ramp like board I put at the tail of the board is there to take the weight off the bag and away from the board rather than have the weight of the bag drag the tips of the blank down. Remember the bag is heavy and the blank is light and easily distorted by the weight of the bag falling off each side of the table. Simple things I have learnt by mistakes.That is why I am sharing it with you.
 Lay the bag out on top of the table and blocks Yes that is all you need.
 My bag is .7mm welded PVC so yes it is heavy and won't stretch, which is what you want to get the most out of the vacuum pump. Remember the bags is being used as a giant clamp. Polyurethane glue will not stick to PVC so you can use it for many boards.
2 sheets of 2mm Paulownia trimmed about 5mm over size all the way round.
 This is flax cloth that I am going to try as a support under the 2mm Paulownia skins.
 Flax, organic and stronger than you think.
 So I have the bottom skin on and no flax under it but I am using it on the deck. You can see the Polyurethane glue is coming through it and will bond to the under side of the deck skin. I always spray a mist of water on the underside of the skins prior to laying them onto the blank to assist with the reaction of the glue. It is activated by moisture which causes it to foam up, which is exactly what you want. So for the same volume of glue you get a lot of coverage and penetration into the EPS beads and a strong bond to the wood.
Top and bottom on and all wrapped up to hold the skins in place as I get it into the bag.

 Slip it into the bag, line it up to your marks and make sure it is sitting on your blocks in the right position, before you seal the bag and turn the pump on.
 As I said the bag is heavy and so it won't stretch , as you can see here it push down and up to join at half way all the way round the rail band. Nice even pressure. Not too much pressure as it will snap the wood as it pulls down over the rail band.
 No fancy tapes and closure mechanisms here, just plain old masking tape. The PVC bag is very smooth and so all you need to do is hold the two faces together and once the pump comes on it pulls the tight together and seals it real good. Also don't forget to make sure that the air in the bag can get to the outlet as the PVC will stick to itself very well. I just use a piece of shade cloth to let it breath.Simple and cheap but effective.
I had to get this regulator as my pump is very powerful and pulls 20 m3 per hour so this scales it down to 10 m3 per hour. Running my pump at low pressure caused it to spit oil and vapour out the breather. It is built to run at full tilt all the time.
So not lots of pressure on this one as the skins are only 2mm and I don't want to squash the foam core. Which can easily happen if you let it pull too hard. I leave it in at least 2 hours to let the glue go off.
So you can see how the new regulator is added in line to control the pressure way down low.
In bed for 2 hours

 OK next up is an XPS or Extruded Polystyrene blank, these are pale blue. Hard and heavy by comparison. So I have to treat this differently. A harder core and lighter shell to see where this goes.It is stringerless but I have added 2mm rail bands.
 This is fly wire, fibre glass fly wire from Bunnings, cheap light weight and strong as hell.
 The plan is to use this to add a little extra toughness to the deck skin by laminating this between the blank and the 2mm deck skin.
 Bottom, just glue and 2mm skin.
 Bottom skin on and the glue is already coming through the fly mesh on the deck.
 Another one in the bag
You can pull the 2mm way down the rail with only light pressure and a good mist of water. I find these skins very dry and brittle, so a little moisture sure helps to loosen things up.

Last of the 4 in the bag - 5ft 4" Hydro V Fish.
So there comes a time when you tidy up the rails and sand them smooth and flush to the rail bands. Mark out the butt crack for the fish tail and bite the bullet with the Japanese pull saw. Great tool. It is always challenging cutting through square and true the first time.It is a game of millimetres.
Here you can see the fly screen mesh under the 2mm skin on the XPS blank.

It feels so good to get all those surfaces to butt together and be flush. Lots going on. Being self taught through making mistakes and learning patients is a good feeling when it laterally all comes together.
 Fish tails three ways.Top one is end grain 5mm sheet which makes it easy to bend around the curve.
The middle one I have done with mulipule laminates of 5mm in the past but went with 20mm thick solid wood this time. Bottom one is not finished but will get another laminate of 20mm thick solid wood and I will cut the curve into it.
 You will see the detail of the end grain when it is sanded down and finished.
 You only need a few tools to build boards this way so if you can have good quality and sharp tools it makes the tasks a lot easier to achieve. That way you just let the tools do the job they are made to do rather than having to attack things with blunt tools.
My happy place.
 The end grain is hard to finish but is easy to bend and comes up great.

 I have found the gun stapler very handy for a quick way to pin things in place like this template.
All ready to add the final 3 x 5mm rail bands to each side.

It is amazing to pull you can get with good masking tape.

6mm sheet cork. Make sure you get a good quality one with fine grain and nice density so that it would fall apart and suck up lots of glue.
 Cork is easy to work with as it will stretch and bend in any direction. But remember if has no structure and so no strength. So even though you are using it as a rail band it is really just filler, you will need to consider a wooden rail band or stringer to add strength to the board if you are not glassing it. You can experiment with different combinations to get lots of flex but be prepared to have it break as well.

You do need a lot of tape as it is soft and moves around a lot more than wood. You can also put on all the rails and bag them once you get a feel with using cork and the time it takes to get it all in place.
 There are all sorts of products out there to help when you have a good look
 Keep adding them
You don't need lots of tools to build a board. Just a few good ones and keep them sharp.
 Looks a little messy but with the right tools it cleans up sweet.
These Japanese Saw Rasps and so good at knocking down the cork and cleaning it up. They look like they are made from hacksaw blades and set up like a cheese grater. Sharp as and so good. A course and a finer one is best.
They are also good to get these end grain bands into shape.

 Then it is time to clean up all the rail bands and foil them to the board before heading off to the shaping bay.
Sharp plane no pain, or disappointments.

The Japanese saw rasp is so good at knocking down these rails and solid Paulownia tails as well.

End Grain on the top makes it easy to bend around the curves and very tough. Solid timber and laminated.
All shaped and now for Mo to glass them.