Surfmat design is a real " inside and outside " kinda deal, you need to see things in 3-D and understand how shapes change as they turn inside out because that’s what’s going to happen.
As an example, glue two curved pieces of fabric or plastic together, it doesn’t have to be a rectangle, maybe choose a tapered shaped with a swallow tail, whatever you like , but I’ll show you how to make it work.
Here’s a half mat sample so you can see what happens inside…
Pic 1. Cut the sides, round the top and glue them together. You need to mark all the design lines and the internal I Beam positions because soon the outside will be the inside.
Pic 2. Now go ahead and glue your internal I beams on the outside of one surface. In this instance I will just do 1 I-beam for simplicity, but it works the same with 2, 3 or 4.
See the little folds and creases along the rounded edge of your first pic? That’s what I get with my heat weld. They are weak points and sometimes leak air. Is that happening to your glue ups?
This green mat is about 6 inches long and held together with sticky tape, so it’s just to show a concept.
Glueing creates smooth flat joins, but I measure everything very carefully, even letting all the parts of the mat sit in the same room so they are the same temperature before glueing because the plastic changes shape as the temp changes. I mark every few inches along sections to be joined so as I glue I know they’re hitting their marks and I’m not stretching them.
The next mat I show will be a clear one so you can see what Im doing.
Pic 1. Looking inside the mat you can see the flaps and I beam and all you have to do is glue the other side of the I-beams in place and close the end.
Pic 2. Put the mat with the Attached side of the I-beams on the lower side, smooth the I-beam down and hold it in place directly under where it needs to be attached to the upper skin. I’ve held it down with a ruler or a flat metal bar or a level or whatever you’re comfortable with.
Pic 3. Now you can see that the I-beam needs to join with the upper skin so apply glue from the back to both surfaces, ( take a few practice runs ) you can even do a single I-beam in several sections so it’s easier to maintain a perfect join.
Pic 4. And then gently bring both glued surfaces together from the back to front. Glue allows you to move the pieces around for about 30 seconds before it sticks so be gentle and keep it lined up, gently run your finger over the join to remove air bubbles and let it set.
Once you’ve got the I-beams in place you can do a normal ‘flap’ join at the tail of the mat but you can do a round or square or bat or swallow tail too.
This is an advanced technique but if you try it, you can create any mat shape, remove the flaps and keep the essential pliability that makes a mat super fast. I will do a more basic mat and technique next up.
The most important part of any mat build is planning.
Surfoils, thanks so much for putting this up. I don’t know that I will build one but it is an excellent read and a very good thing to have in the archives. Many thanks.
It’s cool Greg, mats have a mystery about them but they’re easy to make and ride, soft on the bones and joints and you can be an absolute hell-man on a mat over rock and reef if required. Pumped up hard they are as easy to paddle as a surfboard yet you can let the air out to get under whitewash.
You can sit in them like a hammock out the back between sets and you can build one in a day for $20. Not the same performance as a surfboard but mats are both the entry level for any newbie and also the high end of fluid dynamics knowledge for surfers.
After making surfboards since 78 when I was a kid and more recently making all sorts of conceptual surfcraft for the past 25 years, I figured that I know plenty about mats too and no one else has published how to make them …so why not share what I know.
So the plan is to share what I know, inspire other surfers to try a mat, answer any questions as best I can, no money involved. If you have question about mats or ideas for progressing mat design, drop me a line here and I will answer any questions or build a mat to prove your idea. You can also have any mats I build too.
So even if you don’t have the materials ready, let’s go through the theory and I’ll build a mat to show how it works. This is going to be easy on the math,.
But first here’s what a mat looks like, a top and bottom skin and I- beams in between. As few as 5 pieces to glue so it’s not hard at all.
The next bit is fun, you get to decide what shape your mat is. Commercial Surfmats are around 45 in long x 25 in wide x 5 in thick so you can follow those dimensions or do whatever you like. Commercial surfmat maker often have the dimensions available on their websites so I encourage to visit their sites, read and buy freely of their quality products.
Im making a tapered mat with the nose pulled in but the techniques will be the same. So choose your shape , cut out a paper plan making sure it’s even and then transfer that plan to 2 pieces of material which will be your top and bottom skins. Always draw in a centreline on the outer surfaces or use masking tape to remember which side of each piece is the outside.
Whenever you cut something you need to do it accurately so measure several times, think , stand back and think again before you grab the scissors. Take your time, it’s not a race.
When you have both pieces even, draw on the pieces around the perimeter a line that will be the border where you glue. Or use masking tape to define the line. This glues area becomes the ‘flap’ you see around the edge of all mats.
All of your drawings and tape should be on the outside surfaces so you can peel the tape off later or wash the lines off. Drawing on the material leaves a mark so tape is better but drawing is easier and stays on while you’re building the mat. It’s up to you.
I use a border of 20 mm and so do a few of the commercial surfmat makers.some say the flap has magical properties but for me it’s just where the top and bottom meet and are glued together.
Draw or tape around the border of each piece and make sure it’s even all around and that both top and bottom pieces match.
Now you see it’s all about planning, and the next part is easy too.
We’re going to do the outermost I-beams, one on the left and one on the right side of the mat and the first part is to mark the position where the I-beam will be glued. The sides or rails on a mat inflate to create a rounded semi-circle shape.
The height you have chosen for the thickness of your mat ( height of your I-beam ) is the same distance you draw the I-beam line inside the side glue perimeter line. These will be fat rails but you can make tighter rails by reducing the distance from the glue line to the I-beam.
So now draw or tape a line on both sides to show where the outer I-beams will sit and don’t for get to do the top and bottom pieces and make sure they match.
Drawing a plan of the mat makes things easier to understand and you can use it to design your next mat.
If you went with a 25 inch wide mat then a plan of it would look like this.
Now you have an area between the side I-beams of around 15 inches wide.
If you now put in 2 I-beams in this area it will be a very rounded mat with fat pontoons.
If you put in 3 I-beams it will be a flatter mat, or maybe 4.
Make your choice, divide the area equally and draw in the lines, leaving the same gap at both ends.
You can see from the last 2 pics that the more material you allow for the rails, the fatter they become. And the more I-beams you use the flatter across the deck the mat will be.
You’ve got the top and bottom skins and the plan worked out for the positioning of the I-beams. So let’s cut out the I-beams and then glue them in place.
Measure the length of each I Beam and number them.
If your mat is going to be say 4 inches thick you need to leave more area along the top and bottom edge where it will be glued to the top and bottom skins, so leave a 20mm strip top and bottom. See pic…
Cut out all the I-beams, keeping the lines straight and the fabric smooth but not stretched when you measure and cut. Don’t forget to add the strip for glueing to the top and bottom.
Once your I-beams are glued in neatly, find a valve. You can reuse an old tube from a kids toy or buy something fancy but they all do the same thing…air in / air out.
I emailed a few companies on the net and they sent me free samples.
Pic 1.Below is the I-beams with the areas to be glued folded over and Ive applied a warm iron to create an angle and crisp line so the glueing is precise.
Thanks for the time spent on this. I have spent the last couple years riding mats A LOT. It has been a great addition to my water toys. Mats have changed some of my views on aproaching a wave and board design. I have bought mine from Paul Gross and this is the first thing in decades I did not make for myself. Maybe I will have to try making one. The step by steps offered have answered a couple questions swirling around in my brain. Thanks again for this tutorial.
