Glue for laminating (ie Making a tiller)

[mortehoe]

Thanks oldsaltz (just thae same thanks to everybody else ...

Do you remember 'Bennet Foam' (Surfboards ... ie just asking /forums/images/graemlins/smile.gif )

Your post has set me on a course that I didn't want to go down. I was always suspicious of the absorbancies of oily hardwoods laminated with close grained Russian spruce when using epoxies. 6mm is easy to bend, but I chose to use #12mm because in the past I have been involved with structual 'Glulam' beams where the timber layers are 25 to 60mm thick. But that's an industrial process with ovens.

All in all what you've just said is good advice from an obvious practicioner.

Cheers Mate /forums/images/graemlins/smile.gif I'm going to split the disintegrating tiller up again and go down youre route ...

 

[oldsaltoz]

Re: Thanks oldsaltz (just thae same thanks to everybody else ...

G'day Mortehoe,

You are right in suspecting problems getting some timbers to stick when using epoxy (and other glues).

Some years back I was adding some sugar scoops to a cat and just across the yard this beautiful classic 40 odd foot timber cruiser with acres of varnished saloon and gunwales turned up.

The owners, a group of about 6 had just purchased her and were preparing for an extended cruise expected to last at least 2 years.

They set about removing all the paint on the hull, I thought they were just removing it to re-coat with a fresh coat and took no notice, but for the fact another half dozen people turned up and they swarmed over her like ants and made very rapid progress.

The next day they all the paint removed including below the water line and I wondering what sort of colour scheme they would op for, Meantime I continued my project and when taking a break noticed they were applying a sheet of fibreglass just below the rubbing strake.

I decided to watch a little longer and noticed that other than a wipe with a tac cloth they did no other preparation prior to adding the epoxy resin and placing the sheet over it.

I wandered over and asked if they had washed the surface to remove any oil that might be present in the timber and they replied that had not. I then showed them an area that had traces of oil or some other contaminant that would need washing with Acetone before any resin was applied.

The out come was that I got a letter from them via the yacht club about 8 months later advising the first sheet they applied had delaminated and had to be replaced.
But all of the remaining glass was fine thanks to the Acetone wash down.

Oil in timber preventing good adhesion is not new, many timber boats were sheathed and many shed their new skin, others just roted from the inside unfortunately.


[ QUOTE ]
Do you remember 'Bennet Foam' (Surfboards ... ie just asking /forums/images/graemlins/smile.gif ).

[/ QUOTE ]

Bennet Foam is still around and still imported here in Oz, see link below

http://www.shapers.com.au/category25_1.htm

Avagoodweekend......