This was my first attempt at fibreglassing and vacuum bagging so a lot of the trials and errors where around technique and not so much about design. However, now I've got my sights on doing a better job of it and there are a couple (of many) things I haven't quite got my head around.
Bottom sheet material and what pourable plastics to use for making the rails???
If I go with a nice slick bottom sheeet over the bottom what material would be best to use for an epoxy layup? What thickness, what stuff and what tricks (if any) are there getting it to bond... and how much $$ ??
Also, I used 4mm ABS sheet for the rails on my first board but would like to have a go at pouring the rails on the next one. A friend used epoxy and chopped fibres to pour the rails on his board but it seems like it might be a bit too brittle to be ideal for rails and he found that it tended to crack right through when it had a decent impact. Any suggests on specific plastic products to use for pouring rails?
Plain sealed clear coat will be more than adequate in the beginning. But it is more work for sure. Main reason mass produced boards use PBT is for that very fact, to save time. It does however come with one draw back and that is it traps a lot of resin in the process, makes the board heavier. Nice thing about PBT is that you can print your graphics on it which is really nice, with the added advantage of the protection it gives. Snowboardmaterials.com for 510mm wide sheets I think the link of your blog was for 310mm wide sheets not wide engough for a Kiteboard if it's a twintip. For a speed board 310 would be ok. For graphics you can have vinyl stickers made stick it on your board and clear cat over them to seal it in. A few clear coat layers and you will get a similar effect to say a motorcycle gas tank, looks good and artwork is sealed from the elements. I see you were using plain old hardware store type insert check out Snowboardmaterials.com for the proper inserts. Bought a bunch stainless steel and they come pre-sealed for layup into to your board.
Poured my speed board rails with same epoxy resin I used to layup my board. Do not add any chopped fiber it will dry out the final product and make it brittle as your friend found out. I've had my speed board project with poured rials lying in the garage for two years rail is about 10mmx10mm over a 1600mm very flexible has not cracked even unprotected after all those years. With the layup the strength is further inhanced. You cant see my rails because of the over spray but they are orange. When it's cleaned up I'll post more pictures in the speed board thread.
My board is almost done just finishing off the clear coats. Will clean up the rails counter sink the inserts and it's done.
Some pictures of top bottom base with clear coated graphics.
brilliant. thanks very much for the info. I had watched a YouTube video by Brokites and they had quickly said the name of bottom sheet which from your post I now know it PBT but they mumbled through it so I never caught it.
On the rails issue, what impact do yu think adding qcell/ microballons will have on the poured resin rails?
Your board looks brilliant! What materials are in the construction ? cheers Matt
How did you make that rail? I'm building a carcon board and want to make a poured epoxy rail for it. When I cut out the woodcore I'll save the "left over wood" and use it as a mould. I'll then cut of 0,5mm of thr board and then fill the gab with epoxy. So I got that covered. But afterwards what then? Can I just cut of the rest of the carbon and sand it down to make a smooth rail?
Larse wrote:How did you make that rail? I'm building a carcon board and want to make a poured epoxy rail for it. When I cut out the woodcore I'll save the "left over wood" and use it as a mould. I'll then cut of 0,5mm of thr board and then fill the gab with epoxy. So I got that covered. But afterwards what then? Can I just cut of the rest of the carbon and sand it down to make a smooth rail?
Take the template for your board and route it out on your blank core but don't let router go right through core set it so that there is about 2-3mm of core material at the bottom. This will leave you with a moat/channel to pour your epoxy into. You said you want to pour a rail about 5mm? I would say 10mm is a better bet. When you start exposing the rails (sanding back the flash material) you want to have enough rail to play with should you run into any problems. Also it allows you to change rail shape if you are not happy from say rounded to square.
I use AIREX core material that tends to soak up some of the epoxy, wood tends not to soak up that much. So when you pour the rail make sure you pour in such a way that it is slightly raised and monitor it every few minutes and top it up if necessary before your pot of epoxy goes off. I don't mix any thing else with my epoxy, some people mix milled fiber glass into the epoxy but IMO that only makes the rail more dry and brittle, prone to breaking. You'll be surprised how flexible the epoxy is over the board length. Once the layup is complete this will be fine.
Below are some pictures of a board waiting to have rail poured should give you a better idea.
Larse wrote:And another thing; how did you "end" your carbon or glass? Is it going to stick just fine to the epoxy rail without a chance of delaminating?
Yes just make sure your layup goes over edge of the rail you can sand it down later. I vaccum my boards which gets the fibers nicely saturated. As long as you don't have any dry spots you should have know delam problems. Just remember to roughen up the top and bottom sides of the rails with sand paper for the epoxy to grip on and then make sure the surface is really clean before you layup on it. Simple. It's very satisfing exposing the rails on a hand made board, take your time and it will come out great.
I've splashed out and got some perspex (plexiglass) for the mold surface and noticed that you appear to also be using a plastic surface on you table.
I was wondering whether you found it necessary to use mold release on the surface of it or if the plastic releases easily enough without it. The reason I ask is that I've been applying mold release but the surface is so good that the mold release comes straight off when I wipe it down. So, not sure if I need to persist.
It woudl be great to see some close up shots of your table, in particular the adjustors on the mold surface!!!