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Hi Guys,
Does anyone have any experience using Nidacore panels? It’s a plastic honeycomb that you get with a variety of facings – including a thin birch three ply. It’s essentially a ready made torsion box. We’d like to veneer over it but are concerned about putting the product into a vacuum bag – will it collapse under pressure?
Thanks,
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The web site says the cells are about 5/16 inch diameter. So, your skin has to span that thickness without indenting during the vacuum bag glueing.
At best, your vacuum can place 15 psi onto the system, so the load across the cell is about 1 lb. Since the walls of the cell will support the perimeter of the cover sheet, the unsupported load drops by about half. So, if your sheet can withstand a point application of 1/2 lb applied in the middle of a 5/16 opening, it will work.
Lower vacuum, less pressure.
I suspect strongly that the 3-ply plus your veneer will be more than strong enough.
*Hi John, Quite right. I'm sure the honeycomb will support the pressure from the vacuum. Actually, the web site lists a compressive strength of 188 psi. And we don't generate more than 25 for veneer work. But we're concerned that under vacuum the air trapped in the honeycomb will explode the product from the inside. Any experience with this?Kim Carleton GravesCarleton Woodworking
*Good point!!! I didn't think of that. Most of the composite work I have done was with open celled stuff, so there was a vacuum inside the cells. So, I had the mind set the wrong way.But, I don't think it a problem. Where is the bulging force going? It is trying to push against your vacuum bag. What is pushing the vacuum bag inward? Atmospheric pressure, the same pressure as inside the cells. As long as the composite is fully covered by the bag, I don't think you have a problem. And, in the case of wood, it leaks air anyway, although slowly.The cell walls are not going to move.But call Nidacore yourself. Vacuum bagging is a common fact of composite life, and I would suspect they already have the answers. I have dealt with them in the past and found them very accessable. And, tell us the results.
*John, You're absolutely right! The atmospheric pressures should equal the pressure in the cells. I have some bubble wrap that I can try the theory on.I did put a call into the manufacturer. I'll let you know what they say.Best,Kim Carleton GravesCarleton Woodworking
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Hi Guys,
Does anyone have any experience using Nidacore panels? It's a plastic honeycomb that you get with a variety of facings - including a thin birch three ply. It's essentially a ready made torsion box. We'd like to veneer over it but are concerned about putting the product into a vacuum bag - will it collapse under pressure?
Thanks,
Kim Carleton Graves
Carleton Woodworking