I should have a sample from Nazdar coming too that has a special catalyst designed for ski/board layup (what the difference is that makes it specialised I don't know).
I want to try and use a local product if possible, but Nazdar do have distributors here in Australia.
The inks are both designed for screen printing, but can be thinned enough to use them like a thick paint. My idea was to use plastic or paper stencils and a roller to apply a simple logo to the flamed/abraded side of the ptex topsheet then either use a fabric background or a "flood coat" of a different coloured ink rolled on to the back of the topsheet.
The two inks were an enamel which they recommended, and a two part epoxy ink which I thought would be more suitable given the nazdar ink is an epoxy ink.
Process:
Prepared both inks as per directions
cleaned abraded side of some topsheet with denatured alcohol (metho)
painted the abraded side - two pieces
Allowed to dry for 3 days (epoxy ink suggested 3-4 days drying before layup)
Layup - bamboo, triax glass (wetout with west system epoxy), painted topsheet.
Pressed between 2 pieces of MDF with some books for weight + clamped the two pieces together on 4 corners.
I also did a test on the reverse side with triax glass followed by black 100% cotton wetout with epoxy. I placed a design just cut from a magazine page with a scalpel (shiny paper).
High tech pressing device
Looked pretty good out of the 'press'
But you can see how dull the gloss black is through the topsheet
These are the pieces of topsheet with the paint on the underside
I didn't resand the painted surface or press it in the pneumatic press so as to make it as weak as possible then see if it was still ok.
black cotton and glossy paper graphic
everyone needs a pro model!
another of the painted topsheets
end results
both I had to use a sharp knife to get a run started
The fully delaminated side was the enamel paint - the weak link seemed to be the bond of the paint to the topsheet. It delaminated very easily (peeled off by hand).
The other side that is a little peeled was the epoxy ink. I had to keep working the sharp knife blade under the topsheet to keep it going and could not peel it by hand. It also seemed to pull off some fibreglass as well. It looks like the shear layer was through the ink itself, but in areas it also did pull the fibreglass off as well.
Interestingly when I worked the knife under the cotton side it peeled with about the same ease as the epoxy ink, but the shear layer was between the fibreglass and the bamboo. The bond between topsheet and cotton and cotton and glass was very strong. I hadn't particularly sanded the bamboo before layup, but it was the same as the piece i used in my first pair of skis.
peeling of fibreglass from the bamboo.
Summary:
1. Enamel paint was no good!
2. Cotton for a graphics layer provides a good bond (but adds weight as it soaks up a lot)
3. I feel that the effort to delaminate the piece of topsheet painted with the epoxy paint was pretty high. I think that it is a pretty good ink for back printing graphics, especially if it is only a small area (I feel that if the graphics are small you can just encapsulate them in epoxy between the upper glass layer and the topsheet as long as it doesn't extend to the edge of the ski eg. the shiny magazine paper on the cotton layer)
4. Better transparency topsheet is a goal to create really "poppy" graphics with any graphic method below the topsheet.
and that's my 2 cents!
