View Full Version : Best way to seal plywood and chipboard edges?
Dengue
27th November 2013, 09:43 AM
Can anyone please advise on the best way to prevent the ingress of moisture on the edges of chipboard, MDF and plywood? I am looking for a coating, rather than applying edging.
I am open to all ideas and suggestions.
tea lady
27th November 2013, 10:06 AM
Not sure its really possible to completely stop it. Paint the edges with oil based paint might slow it down a bit. If its gonna get wet you might need to use something else.
son_of_bluegras
27th November 2013, 11:32 AM
I deal with this at work. We use an exterior silicon caulk/sealant. It still doesn't stop it completely but does extend the time to replacement.
ron
Arron
27th November 2013, 04:18 PM
Wouldnt marine epoxy be the best thing. Thats what its designed for.
Arron
Robson Valley
27th November 2013, 04:25 PM
What are the service conditions? Indoors or outdoors?
Solid woods stand a better chance of dying slowly when compared with veneer/particle mass.
Far too expensive for small jobs but for outdoor service, like tables, chairs, log homes, etc
Sikkens Cetol is #1, #2 and #3 choices.
Epoxy might be OK if you can dilute it 10% with some sort of solvent, up the catalyst and
hope some soaks in before it sets. We used propylene oxide.
Dengue
27th November 2013, 04:42 PM
Will be used indoors. No one has suggested shellac, possibly thinned to sanding sealer dilution?
Master Splinter
27th November 2013, 06:41 PM
Marine epoxy.
Weight gain of bone dry test sample (with three coats of epoxy) after 8 weeks at 40 degrees C and 100% relative humidity - about 6%
If you want better performance, you'll have to coat it with paraffin wax.
WEST SYSTEM - Projects - Moisture Exclusion Effectiveness (http://www.westsystem.com/ss/moisture-exclusion-effectiveness/)
Dengue
27th November 2013, 07:19 PM
I have some Sikkens Cetol left over from when I painted my front door a couple of years ago. My understanding is that it is basically a stain that is waterproof, but it is 'micro-porous' and allows the timber to breathe.
I thought it excellent for the tightly grained door surfaces, but would not be much good for the edge grain of chipboard and plywood, which is my problem area. I am very willing to stand corrected here.
son_of_bluegras
28th November 2013, 11:28 AM
More information please, if it's indoors what conditions are you concerned with?
Ron
Dengue
28th November 2013, 01:48 PM
It will be used in a shed, which is not air tight. We have very high humidity in the tropics, 100% quite normal on early summer mornings, so don't want the chipboard and ply soaking up moisture from the atmosphere , swelling and deteriorating. And now with our summer monsoonal wet season approaching, it is important that the edges are sealed.
It is for the edges of the horizontal pressure panels on this veneer press.
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son_of_bluegras
29th November 2013, 10:52 AM
If you don't expect water to condense resulting in direct contact with the chipboard and ply than anything that seals the edges should work. That could be shellac, glue, caulk, epoxy, paint, wax, oil, the list goes on.
Given the application, I'd be tempted to wax everything (with the idea of preventing any glue from the veneering process from sticking to any part of the press).
ron
RETIRED
29th November 2013, 11:38 AM
We have used fibreglass body filler to seal the edge of plywood and chipboard but you may have a keying problem on MDF.