Thursday, November 24, 2011

Starting on the core at last!!!!

After many distractions, a couple of other projects and a fair bit of time sourcing materials for the boards I finally started on my first wood core. Only a baby step but it feels good to be  moving forward.

I decided to build the core up our of 6mmx100mm Paulownina planks instead of starting with a thicker core and cutting and routing it into shape. I don't have particularly good tools to work with so for this board at least I'm trying to minimise the work.

Tonight I stuck the planks together (told you it was a small step!). I had intended to slice them into 50mm widths and mix them up to average out the weakness in the wood by shuffling the planks but the strip cutter that I used for balsa previously wasn't up to the job of cutting the much denser Paulownia. So instead I decided just to work with what I've got until I can put together a small table saw to make sure I mill the planks perfectly.

So, the first thing I did was to squeeze the planks together and put masking tape on one side of the board. The idea is to use the tape as a hinge to make it easier to get the epoxy into the join and stop the resin flowing away.

Tape hinges to retain glue and apply some initial pressure to the join.

Tape hinge made it easy to 'wipe' glue along the vertical surface and have it run into the join before closing the join to squeeze the resin around.

Found an extra use for the angle iron of the rocker table. With the angle iron piece used to support the center jig I squeezed the planks tightly together. I put the tool box on top so that when I tightened the ratchet strap it put pressure down on the MDF board templates its sitting on at the same time as the strap squeezes the planks together and so that the freshly glued joints where nice and tight.

Next step is to cut out the layers using the router. First time using one so should be interesting!!!


  1. Good stuff!
    I normally use a double side tape to secure the template on a plywood, than clamp everything.

    Will you leave a wood grain exposed or paint it?

    I've been reading that my ply wood will spring back and forgotten to take this into account.

    This might be important if it's really 30-40% :(

    Will check at home and report back!

    Also, is your epoxy going yellow over time? Or you varnished it with UV protection?


  2. Hey Dean. Yep all good tips. Thanks for the double sided tape idea. I was wondering how to handle it on my own. Cool!. I am going to leave it exposed on top. The epoxy I use goes yellow after about 1 day in the sun ( apparently there is no UV stabalised epoxy - seems amazing - but I actually quite like the 'aged' look that it gets. Have you found a UV protective varnish that sticks to the epoxy well?

    I've built 20% spring back into my board. I thought I might glue the top and bottom deck together on the rocker table so that there is some curve in them already and maybe this will reduce some of the spring back.

    I got a sauce bottle today to use for pooring the rails!! I couldn't find a big syringe so this seemed like best alternative.

    For your rails did you route the channel all the way through the core or leave a bit on the bottom?


  3. No probs.
    It might be that epoxy is going yellow anyway and even more on the sun.
    I think the West S. 105/207 is a go! 207 is clear and will stay like that if protected (they say:) Just got Goldspar glos varnish and will see if sticks.

    Can you squeeze a sauce bottle? I've got now a 60ml syringe!!! That is a horse size:) They are ~$2.5 and can send to ya. This is the biggest size ever seen here.

    I routed ~4mm out of 6. Now thinking it would be better to route a smaller channel to save epoxy, mine is 12mm wide. But really should this be on the bottom or top?
    Since my rails are damaged mostly on bottom side.


  4. Hey Dean.
    The sauce bottle is a soft plastic one so it worked well. Holds about 300mls. I put a snap up on the blog.
    I had a chat with the guys at FGI (fibreglass international) and they reckon that no epoxy yet is UV stabilised so will all go yellow over time with exposure to sun is not coated with something.

    The fast harnder for the R180 resin I bought starts out a honey color (which I really do like) but the standard harder ( 30 mins pot life) is clear. I've seen a few people using the west system resin ( I like the pump packs - handy). How long after its cured do you heat cure it or do you do it at the same time? The R180 I've got says to cure it 24 hours after the initial curing to improve cross-linking. Seems unintuitive but that was confirmed by FGI..

    I'm thinking I'll route all the way through the 6mm and use tape on one site to create the mold. The top deck on this board is going to run over the rails I want it to come all the way to the top. I have a bad habit of hitting rocks on the tips of my board so I need all the reinforcement I can get as well.