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question about heating wood

Posted: Mon Apr 23, 2012 10:43 am
by vinman
I'm going to be using my ski epoxy to bond a full 10.25" stick of sidewall material to a 10.25" thin piece of wood. To do this I'm going to resaw and plane some hardwood down to about 5mm. Then I'll spread some epoxy and place the sidewall on it and cook it in my press with mild-moderate pressure 10-20psi maybe, so I don't squeeze out too much epoxy. After things are cured I'll rip it into sidewall strips and glue them to a core blank.

Now my question is, if I use my existing 4mm camber mold will the heat and the curing of the epoxy give me a permanently cambered board (wood+sidewall) or will it flatten back out? Or if it flattens back out would it stress the epoxy bond too much?

Should I just build a flat mold/spacer for my press to accomplish this?

Or should I just put it in the camber mold ptex side down to intentionally give it some camber and make it easier to glue to the core blank?

Would a cambered stick be too tough to saw accurately?

Posted: Mon Apr 23, 2012 11:44 am
by MontuckyMadman
4mm is pretty minimal.
I's sure it will fall a bit and 4mm is easy to flatten if cutting on table saw or bandsaw..
Should aid in shaping to the sidewall. I think you are good to go.
Report back.
Might want to make a sandwich with wood for profiling like head monkey did. Gonna be hard to bend to shape in some spots depending on sidewall profile.
Depends if you have problems with the plastic sidewalls coming off during profileing.
I am pouring urethane on venneer for the same type of thing.

Posted: Mon Apr 23, 2012 11:57 am
by chrismp
MontuckyMadman wrote:I am pouring urethane on venneer for the same type of thing.
that's a clever method! but i still don't understand why you don't use my method and cut a channel into the core? it saves you the hustle of using tipspacers...

Posted: Mon Apr 23, 2012 12:31 pm
by Richuk
Vinman,

I get camber from a flat mold when I do this - I haven't gotten round to adjusting the cure cycle.

Good luck.

Posted: Mon Apr 23, 2012 12:35 pm
by vinman
I think maybe the sandwich is a good idea. I was figuring the first 2-3 inches would be sacrificial and would be cut out to do my tip spacers. I was also going to put about a 60 deg angle on the sacrificial stuff at the tip to create less material for the planer to potentially catch on. I may also put a mitre on the tip end piece to allow for a gradual angle for the planer blade to see.

Posted: Mon Apr 23, 2012 12:57 pm
by vinman
I think I'll use feather boards to hold the material to the rip fence and to hold it down to the table.

I guess I'll go with p-tex side down on the 4mm camber mold with maybe 5-10 deg extra on the top heat.

Posted: Mon Apr 23, 2012 2:18 pm
by MontuckyMadman
chris our skis have a big tip bend, so plastics easier. our core sleds are made for the wood core, square or rectangle.
Our blank before bookmatch is 30mm, that would be allot to plunge rout and channel, or so my wood guy thinks. I understand.
If we bookmatch and then rout we have to route twice. I'm sure we will try some like that at some point.
My sled is not really conducive to cut the core like that but we should try.

Posted: Tue Apr 24, 2012 11:43 am
by vinman
I'll report back as soon as I get mh planer back. The bearings are shot and it needs a new belt. Parts might take up to 2 weeks according to the shop... Bummed, my order from crown (12+ pair worth of material) should be here today or tomorrow.

Guess I'll just have to work on everything else except for the sidewalls.

Posted: Tue Apr 24, 2012 4:45 pm
by teleman36
This is a great way to make sidewall units for use in any shape core. We used to epoxy up multiple 30 -34 mm strips of pe to 5 mm pieces of ash or poplar with a piece of VDS in between. We would make up dozens of these units and put them in the racks for future use. It is now easier to use the press with flat plattens to make up 3 5" units and then rip to whatever you need. This method gives us more flexability because our cores run from 7.5 to 11.5 in thickness. IMO heat has no bad effects on your 5mm wood. This opinion is based on being an old fart that has made boats and canoes and Windsor chairs over the years, and as a ski maker I think it is a non issue given the fact that the wood will be inside a layup. Check out the Aluflex videos. Some of the Euros seem to have designed there presses just for this application. This is way past my typing tolerance limit, so PM me with your # or to get my Cell # if you have any more questions. Later, Mark