jerryferry

Member

Registered: 13 Jun 2011

Posts: 18

Bubbles under cloth???

I'm considering building another boat a few years ago I built a canoe and got into trouble when applyig  the cloth. It all looked good when I had finished but whenI  came back the next day there were tiny air bubbles under the cloth. I had to paint the outside rather than varnish.  I was told that this was some sort of gas from the wood, has anyone solved this.

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Lifelong Angler

Richard

Member

From: East Sussex

Registered: 7 Jun 2011

Posts: 75

Re: Bubbles under cloth???

Not many people on this new forum yet so I feel obliged to respond but I have not had this problem.  I followed the instructions in the manual and put the cloth on the bare wood before soaking it with epoxy.  I have heard of people coating the wood before putting the cloth on. Perhaps  this causes it.

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Canoe & Kayak Owner

Phil

Employee

Registered: 8 Jun 2011

Posts: 68

Re: Bubbles under cloth???

It all looked good when I had finished but whenI  came back the next day there were tiny air bubbles under the cloth.

What you are referring to is off gassing.  As the plywood warms it releases gas bubbles which were trapped below the fabric.  The way to avoid this is to keep the temperature constant during the curing stage.   In practice the best method to ensure that your fabric is free of bubbles is to warm your shed and wood before you start the work and then to turn the heater off or down once you start the soaking of the fabric.  Another way around the problem is to start the coating in the afternoon so that the ambient temperature falls as the epoxy cures.  The drawback of this is that if you want to avoid sanding and want to fill the weave five hours after finishing you will need to go back into the shed in the middle of the night.

You will find a lot more information on this subject on this link:  Coating wood with fabric

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jerryferry

Member

Registered: 13 Jun 2011

Posts: 18

Re: Bubbles under cloth???

Thanks for your replise both of you.  Sounds like temperature is the answer - teh page Phil linked to says keep the shed above 15C but turn off theheating when you start so it doesn't get warmer. There are some more useful epoxying tips there too - got it bookmarked for later

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Lifelong Angler