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Re: Kiteboard graphics, need advice

Posted: Sat Jun 02, 2012 8:58 pm
by mikellli
foam-n-fibre wrote:Do a test with the silk and make sure it does not peel off like peel ply. Generally only cotton is used for graphics, but I have no idea about silk.


Reading the forums, I concluded that cotton and silk can be used, but only when they 100% natural.
Đ•ven more, silk is apparently much easier than cotton...

However, I will listen your advice and test how the silk behaves.

By the way Peter, thank you for your videos, they really inspired me and interested for all of this.

(sorry guys for bad english)

Re: Kiteboard graphics, need advice

Posted: Sun Jun 03, 2012 5:13 am
Any opinions about screen printing on silk or straight onto carbon cloth then doing layup.

Re: Kiteboard graphics, need advice

Posted: Sun Jun 03, 2012 5:33 pm
by mikellli
I just sprayed silk with some sprays that I had.

Disaster, silk is stiffened, cracked paint, color coverage is very poor. I was very disappointed, I'll try to find screen-printing ink, and paint with the spray gun.

I have not even tried to laminated the silk today...

Re: Kiteboard graphics, need advice

Posted: Thu Jun 14, 2012 9:13 am
by mikellli
I managed to do a little test with silk. Screen printing turned out great. But the lamination is another story. I was laminated 10x10cm piece of plywood with (from botom to top) 2X160gr glass, silk,160gr glass. Laminate was turned out too dry, the top layer fibers were seen. It seems that the -0.9 bar of vacuum is too much. Since this is my first laminating, so I can not know how much silk should be strongly adhered to the glass. I left the edges without resin, so I can use fingers to separate the layers. It took considerable force to partially separate the silk of glass, the same strength which I separated the two layers of glass... Laminate is a very bad, turned out very dry, very easily separated from plywood.

I'll have to do more tests but I need a little help that would shorten the time for testing. You see for each test I need at least one day.

How much should be a force of vacuum?
How strong should be a composite to know that the silk is suitable for this job?
Is there a catch, to make resin better sticks to plywood?

Next time I will post pictures.

Sorry guys for the bad english.

Re: Kiteboard graphics, need advice

Posted: Thu Jun 14, 2012 12:37 pm
by zob
It looks to me, you have a problem with resin quantity.
For tests I mix too much of it, so I can make the test perfect.
Look. Plyboard soaks up some, silk probably too, and there are these empty spaces in the cloth, that need to be filled.
If everything is soaked up enough and all the air is forced out (which in your case probably is since you use a vacum pump), the graphics will be perfectly visible and the laminat will be transparent.
However, aplication steps are also important.
If using ply, you should apply excess resin mix on the ply, distribute it (stil leaving a thick layer), than apply cloth (or graphics) and gently stretching it to the board (from the center out), add a bit of resin and gently distribute it and add next layer of cloth,...
If you didn't hurry too much, the ply has soaked the amount of resin, that it could, so now you can squeze all the excess resin out (from the center out), alining the cloth at the same time.
But again. Don't remove too much of resin, because you will produce bubbles in the top cloth layer. Use peel-ply and breather cloth!

Re: Kiteboard graphics, need advice

Posted: Fri Jun 15, 2012 6:29 pm
by mikellli
Thanks Zob for your advice, next time use much more resin. But I still think that the power of vacuum is pulled resin in cotton that I used as breather next to laminate

Re: Kiteboard graphics, need advice

Posted: Thu Jun 21, 2012 10:12 am
by Hollow
Use a fine weave fiber cloth on top layer in order to get smooth surface. Max 80g/m2 plain weave.
Also you can try to use a perforated sheet of PE instead of peelply or separation film. It will improve the surface quality too.
Pressure has nothing to do with dry fibers. The greater the pressure the more compressed fibers are.
To high vaccum can cause the little bubbles to appear in the composite but not the "dry" fibers.
It is a lack of resin.
Use an epoxy resin not polyester if you need good adhesion to wood and better final result.
Mix more resin next time.