DIAB Foam

Herman,
You mentioned you had comparative data for adhesion of infused laminates against sanded or peel ply prepared substrates, its this relative data I was referring to.
Also if you have any comparative data for infused versus vacuum bagged versus hand laminates, once again same materials but different process.
I have never been able to find this process comparative information on the net.

Of most interest would be secondary bonding, because of the much lower resin content is infusion of tapes as good as hand laminations. Ie which has better interlaminar peel strength?
The answer may be to infuse but use a tape with stitched CSM backing to increase the resin content at the bond?

Cheers
Andrew

 

Ruby Tuesday
I post cured my 12m catamaran hulls in a simple plastic tent and a small gas fired blast heater and about 6 fans circulating the air. I also put inexpensive foil backed bubble wrap on the roof of the tent to provide some insulation. This achieved a temperature range of 50 - 60'C inside.
A friend partitions of his workshop with 100mm styro foam sheets and he achieves 75'C.

 

About heating: If you want to do a slightly more sophisticated setup, there is also sheets available made from thin metal sheet, with a PU sandwich. With a bit of planning one can make a great removable oven. Also, keep in mind that the floor causes a lot of heat loss as well.

About secondary bonding:

No hard data. The tests I did were very simple, and very crude. I layed up a gelcoat, a barrier coat, and a skincoat. I divided the skincoat in 4 portions.

-1. Let cure, no prep at all
-2. Sprinkle short glass fibers in the wet skin coat
-3. After cure, sand well by hand, grit 40
-4. While still wet, apply peelply

I infused an epoxy resin behind it, with some layers of 1200 grams quadrax, some Lantor Soric to create thickness, and again 1200 grams quadrax.

After cure, and after 7 days, I tried to peel the skincoat from the laminate.

Results:

-1. Easy to peel. Useless
-2. Easy to peel. I expected more from this solution. Seemed that the bond of the sprinkled fiberglass to the skincoat was less than expected.
-3. Slightly harder to peel, but still doable. I could slice a chisel through the bond line.
-4. Very hard to peel. With a chisel, I could only remove "scales" of skincoat, 10x20mm at the time (3/8"x3/4").

No hard data, though....

I wished I had the equipment to do more thorough testing. There is so much I would like to learn.

Right now I am setting up a program to do certified fire resistance tests with all kind of laminates, mostly for the building industry. Will keep looking for a pre-owned tensile / compression / shear / peel tester though...

 

Hi Andrew,

I also put up a tarp tent over the hull & deck (separately) & managed to get a temp of 60* for a few hours with two gas heaters, but nothing like the 12 or 16 hours others speak about?

We did all our secondary bonding with a 600DB with 225 CSM stitched on & have had very good results ( I think it’s referred to as 1708?)

Cheers