I've been looking around at different options for graphics and thought I'd share the few things I've found out.
The most common production board approach is to use a high density, abrasion resist plastic film with the graphics printed on the underside using dye sublimation printing. The typical film material its printed on to is PBT or UHMWPE (ulta high molecular weight polyethylene) which has product names like Durasurf or PTex and is commonly used as a bottom sheet for snow boards. Problem is it seems to be near impossible to source in Australia. Snowboardmaterials.com in the US sell it and will print your graphics for $50 but the shipping cost is about $150!!
Dye sublimation printing can be used to print onto othe synthetic fabrics and is used to print promotional material ( flags, banners etc) on polyesther fabrics. This might be an option if the polyesther is light weight with a big enough weave for the resin permiate. A local printer I spoke to suggested giving Trilobal Polyesther, commonly used in printing flags, a go. He said the weave is open and it holds a print well. Some further googling on polyesther fabric and epoxy turned up some info from a boat builder forum that suggests that certain polyester fabrics with epoxy are used for abrasion resistance in wooden boats. The one issue they point out it holds about 1.5 -3 times the resin that equivalent weight fibre glass does so it will add weight to the board. However, lots of other benefits if it works - drapes across 3-d surfaces, abrasion resistant, printable with photo images. Definitely worth an experiment. Pricewise, it going to cost $50 setup fee and $80 per meter but the width is up to 1850mm so you can get 2 full sides per meter or 5 on 2 meters of material so the price is in the territory of PBT etc.
Because plastic inherently has average to poor bonding with resins some of the PBT material comes with a 'fur' called remay on the back which hold extra resin and assists with bonding. However, its not see through so if you want to show off you wood core it won't be ideal and it also holds extra resin which means extra weight. I believe that the film without remay on it requires a good amount of heat to get a good bond. On this topic I was speaking to a sales rep at Dotmar plastics and he was telling me you can get one side laser etched and this helps dramatically with bonding the film.
Anyhow I can't get hold of the material cheaply so this is all academic.
The other approaches I've read about are to use stickers on the finished board and paint over with Clear Coat to protect them. However, this relies on the strength of the sticker adhesion which I suspect will not be good for long and especially if it takes a beating now and then.
The other, more viable option, is to print the designs on porous, translucent material and put it under the glass during the layup. Turns out its as easy as using an inkjet printer and printing on cotton, rice paper or, I suspect, any light weight paper. This would be ideal if your graphics are less than A4 size, for example, like a series of differ geometrical shapes or photos.
I recently spoke with a guy at our local beach who had just been over for a tour through the Decay Boards factory in NZ and bought a couple of great looking wood grain finished boards. He said that they printed on silk and then encapsulated them in the layup. Looked great.They graphics were translucent so you could see the core. Silk also is pretty strong in its own right so may contribute to the strength of the board.
I looked around our local area for printers who could print onto silk but again no luck. A google search turned up some inkjet printable silk sheets that have a backing paper on them that helps them run through the printer. I could only find a US source for these as well. However, it turns out that Quilters have been successfully creating their own paper backed fabrics (silk, cotton etc) to inkjet printing. They use 'Freezer Paper' which is paper used to wrap things to put in the freezer (clever name hey!) It is normal paper on one side and has a thin plastic coating on the other. If you lay your material on it and iron over the top of it the plastic melts a bit a sticks to the fabric. Apparently you can then run it through the inject printer and then just peel the freezer paper off.
This seems like a great option for decals A4 or smaller.
There are 2 drawbacks.Firstly, the PBT/ UHMWPE provides a scratch resistant surface whereas encapsulating the graphics doesn't add anything. If you're going to encapsulate graphics it might be a good idea to have s-glass as your last layer on the board as the extra strength improves impact and abrasion resistance. Secondly, your limited to images less than A4 size unless you have more luck in converting your injet printer into a continuous feed printer (I am sure there is a way to supress page breaks. Anyone, anyone???)
Googling around I came across an obvious and exciting option (obvious once it presented itself ,not obvious because it was obvious before). 'Glass on Surfboard decals' . These are digitally printed and are designed to be encapsulated in the fibreglass. Turns out there are a few suppliers not too far from where I live. Check this out:
These guys print on high tensile strength cotton so it will work great.
These guys, based in Burleigh Heads near where I grew up, print on silk and have have done some SUPs as well as boards.
I've emailed off to get a price and expect that it will probably come in around $60 per side based on the prices on their website for a full surfboard size decal This is a big chunk of the price of the board but the results are amazing. If you google surfboard graphics it turns up loads of producers. Obviosuly it would be half the price per board if you did not cover the entire surfcae area of the board.....
(UPDATE - the decals printed on silk from StrykerMedia came in at about hald what I expected!!!!).
This is the image that I'm keen to get on the underside of the board. It joins it self as well so can be extended to the full length of the board although stretching it out looks good too.
|The great wave off kanagawa by Hokusai|