Introduction: Build a Fiberglass XPS Foam Core Skimboard

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About: Amateur product engineer, 3D artist, illustrator, inventor and designer.

The building of a fiberglass xps foam skimboard varies from company to company.. Different skimboard crafters have different techniques and processes. The technique I developed in this tutorial took me over 3 months to develop and resulted in a lot of wasted materials until I finally created a professional performing/looking skimboard. .The challenge was hard but ultimately very fun once I got the process down. I illustrated this tutorial of the step by step process to help present a clear and resourceful way of producing your own fiberglass/xps foam skimboard.

This guide shows the different layers of a skimboard which you will be creating.

  • 1 foam core
  • 4 layers of 4oz fiberglass cloth
  • 4 Layers of Epoxy resin on the fiberglass cloth(part A and B mixed)
  • 4 Layers of Epoxy resin as a top coat (glassing layer) On top of the cured/hardened fiberglass layers.

My top suggestions before you start on this project is that you have patience, practice proper safety, and work slowly and accurately.

Fiberglassing and Epoxy are very toxic, sticky materials to use and take time to cure/harden properly. Don't get discouraged if the materials are hard to work with. The most challenging steps are the first ones.. Good Luck!

Step 1: Cutting the Board Out of XPS Foam.

Here we go! The first step! The absolutely most affordable quality foam option available at your store is from Lowes hardware store. It's called Dow Polystyrene Foam Board Insulation but on the Dow website it clarifies that it is a XPS foam material.(Expanded Polystyrene). This stuff is waterproof, lightweight and cuts very clean. The dimensions are 0.55-in thick x 4-ft x 8-ft. But after all the layers of epoxy and fiberglass you'll get a thickness of around 0.75 inches. This sheet is enough to make 3x55" skimboards if angled correctly. Plenty of material in case you botch a first or second attempt. ha!

I created a stencil and had it printed on Vistaprint.com of half the board and had it laminated and printed on a 36x48" sheet. The board I created was for a 55" tall by 22" skimboard. I used the stencil after cutting it out of the sheet on the board and marked the outline with a marker. I repeated this for the bottom half of the foam.

Here is the adobe illustrator file of my stencil as well as the jpg if you want to order a large format stencil from Vistaprint.

I then used a box cutter to cut out the shape from the foam making sure to have a very straight vertical angled cut.

Step 2: Beveling the Rail of the Board

Using a super fine-grip foam sanding sponge/block similar to this I beveled/sanded the top layer of the boards edge to a smooth angle. Note: Only the top level/one side needs beveling. Try to create a smooth bevel only eliminating a small portion of the foam.

I highly suggest at this point getting a breathing mask to not inhale the dust from this foam. You will need this later on in the Epoxy/Fiberglass stage.

Step 3: Creating the Rocker or the Front Tail Bend.

So this was a challenge but the technique that worked for me was putting two large weights on the lower 75% of the board (i'd incorporate a fold out table to place this on). Underneath the front tail place a round object with the right height that you'd like the front bend to make. I used a broom handle. I did a 20 degree angle bend.

Here comes the hard part. Using a heat gun very lightly in short passes I was able to make the bend maintain it's shape. I don't recommend putting the heat gun less than 1 foot over the foam board. YOU don't want this to burn or melt! It takes light passes several times to have the foam keep the bend shape. Do this part slowly and cautiously with a mask.

Step 4: Mounting the Skimboard for Fiberglassing

Using a Trestle similar to this you want to securely attach the foam board to the base similar to the diagram using this type of thick masking tape. Make sure the tape is on strongly so that the board does not fall off. You'll be using this masking tape throughout the whole project so buy plenty. DO NOT use blue painters tape or frog tape. This generic masking tape is strong and is more secure for edging later on in the project.

Step 5: Edging Your Skimboard for the Fiberglass Process

Now that you have your skimboard securely attached to the Trestle it's time to edge your board to keep future usage of Epoxy resin from dripping underneath the board in the next couple steps. When you edge with the masking tape (same as the mounting stage) you protect the bottom of the board from epoxy drippings but also save yourself from having to do excessive sanding around the edge later on.

Very important: When you place the tape on the board make sure to edge the very bottom base edge of the board (not underneath the board) Later on this tape will be removed hopefully leaving a clean line.

Step 6: Fiberglass Laying

I suggest and have used 4oz fiberglass cloth from this place Greenlight Surf Supply. These guys deliver high quality fiberglass cloth at very reasonable prices and they ship practically overnight. Fiberglass Cloth 4 oz x 30" wide x 7 Yards worked for me and gave me enough for 4 layers total which is what I needed.

Step 7: Trimming Your Fiberglass Cloth

This is where intricate detail is required when cutting and trimming your 4 layers from the cloth. Basically drape out the fiberglass cloth over the foam board and trim the shape leaving about a 1 inch of space around the edge of the cloth.

Take your time, and cut very slowly and acurately. Don't worry too much about fraying the edge but just try to create a clean cut around the edge making sure to do 1 inch of excess cloth. I used a hobby craft knife/Exacto to achieve a very clean line. You will need a very sharp Exacto knife later on in the epoxy portion of the project.

Step 8: Trimming the Fiberglass Layers

The fiberglass should drape nicely off the edge of the board overlapping over the masking tape. Make sure you have two layers cut out at this point which you will be using Epoxy resin to paint/squeegee on next.

Step 9: Epoxy Resin - the Hard Part

Epoxy is the resin that binds and hardens the fiberglass in to a tough shell on the skimboard. It's made up of a two part A/B resin which when mixed for 2 minutes thoroughly it can be poured on top of the fiberglass cloth and spread out or brushed. It's very important to stir this thoroughly.

I used this Epoxy Resin because of it's affordability and quality but other surf suppliers might recommend other brands. They also deliver very fast. This 1 gallon epoxy resin is more than enough for the rest of this project. I bought more later for a thicker coat but this should work fine.

These cups are great for mixing epoxy and are disposable. The amount of resin that worked for me for the first layer of epoxy is 2oz of part A and 2oz of Part B.

Safety: Wear a breathing mask, nitrile gloves, and try to work in a ventilated area. I also encourage eye protection.

Step 10: De-gassing Your Epoxy Resin for No Bubbles

OK so this is not necessarily needed but it's highly recommended. A Vacuum Chamber uses a compressor to remove bubbles by suctioning out the bubbles that show up after mixing the two part epoxy resin. I bought my Vaccum Chamber from here and it's reasonably easy to use but do follow the directions on how to use it.

Basically you would place the cup with the A/B mixture after being stirred for 2 minutes in to the Vacuum Chamber, cover the top of the container, switch on the compressor and it should suck out 90% of the air bubbles. This video explains clearly how to do this but it takes a lot of attention to detail to make sure it is done correctly.

Your resin when pouring on to the board will be crystal clear with no bubbles. The other option is using a heat gun to target bubbles after it is poured which works well also and is a cheaper option.

Step 11: Pouring the Epoxy Over the Fiberglass Cloth Layers

Once your epoxy is mixed and optional (vacuumed for bubbles) comes the pouring part. Place both layers of fiberglass cloth over the board. Make sure the cloth is aligned exactly with a 1 inch overlap even on all edges.

Pour the resin on top of the board making sure there is an even coat. I prefer using a disposable paint brushes like this but a plastic squeegee also works fine. Slowly spread the resin and make sure every inch of the fiberglass is covered. Make sure to make it drip off the edge as the fiberglass cloth edges needs to be coated. The masking tape will pick up the excess dripping of Epoxy resin. Basically cover every bit of the fiberglass cloth leaving no dry areas.

Layer 1 of 2 is done. Let this layer dry for about 2 hours till it's cured to a sticky/tacky consistency before you mix a second batch of epoxy resin to pour for the second layer.

Safety: Wear a breathing mask, nitrile gloves, and try to work in a ventilated area. I also encourage eye protection.

Step 12: Using Your Heat Gun to Eliminate Bubbles in Your Resin

If you don't have a Vacuum Compressor you can use a heat gun to pass over the board lightly to make sure all bubbles are eliminated. Bubbles will add many cosmetic effects to the cured resin on your board. Even with polishing they can still be visible.

Step 13: Removing the Edging Tape and Cutting the Excess Fiberglass Edge.

It's very important after the 2 layer epoxy pour that you let the second layer cure for about 2 hours. You want to check for a tacky, sticky coat and that signals that the edging tape can be removed easily before it fully hardens. If you wait too long the tape will be harder to remove.

Using your very sharp Exacto Knife you want to cut just above the masking tape in to the fiberglass cloth and then carefully remove this excess layer with masking tape.

Even if you cut slightly in to the foam you want to make sure you cut a precise layer of the epoxy/fiberglass while it is still tacky. The harder the cured epoxy shell the harder it is to cut the fiberglass out. The diagram shows the cut line recommended.

Step 14: Flip Your Board and Repeat on the Other Side

After the tape and excess fiberglass layer is removed with the Exacto knife let the top layer cure overnight or for more than 4 hours. This is where being patient is key. The fiberglass layer should be hard and dry. If that is the case then you can flip the board and repeat the process of taping the other size of the board to the Trestle. The masking tape at the bottom of the board securing it is very sticky so remove carefully.

Mount the board on the other side then it's repeat time.

Step 15: Repeat Fiberglassing on the Other Side

Repeat layers 9 - 17 making sure you tape a very clean masking tape edge on the other side.

YOU Want the bottom layer of epoxy & fiberglass to overlap the top layer of the board shell in this process.



Step 16: The Importance of Overlapping Your Layers

Make sure once again that you will be overlapping the next layers on top of the top layer of the board. Like the diagram:

You want the bottom layer of fiberglass to overlap the top layer of the board so the entire board is bonded together.

Step 17: Sanding/Prepping for Glassing Your Board

Once you've got that hard shell of epoxy and fiberglass cured it's time for prepping the board for glassing where you will be a nice smooth coat of epoxy on each side of the board. For my board I used a hand sander for this process similar to this


You want to sand out any imperfections using a medium grit. Polish the nose of the board, the rails, the edges etc. You won't get it perfectly smooth but enough to get out any big imperfections.

Next the glassing phase

Safety: Wear a breathing mask, nitrile gloves, and try to work in a ventilated area. I also encourage eye protection.

Step 18: Glassing Prep: Edge the Other Side of the Board

Similar to the earlier steps you want to use masking tape to edge the lower portion of the board. This is going to save you tons of headaches later from having to sand and polish. This tape protects the board from drips underneath the board from the epoxy.

Note: When edging with tape make sure to edge the very bottom portion of the side of the board similar to the guide. Remember the tape is there to mask off the other half of the board from resin. Epoxy resin can and should cover the masking tape in this process.

Step 19: Glassing Your Board

Glassing is basically the process of putting 2 or more smooth coats of epoxy on top of the board. This is also the stage where I encourage you add color. I add about two drops of this epoxy dye and mix thoroughly.

Amounts of epoxy to use vary but one layer should be about 4oz. 2a-2b

While mixing up a new batch of epoxy to spread/brush on your board you must make sure to

1. Vacuum out your resin

2. Pour slowly all over the board

3. Brush out the resin evenly all over the board.

4. wait about 2 hours for the resin to get tacky/sticky

5. Repeat for the second layer.

Safety: Wear a breathing mask, nitrile gloves, and try to work in a ventilated area. I also encourage eye protection.

Step 20: Glassing: Heat Gun Your Bubbles Out

You can heat out bubbles this way again if needed.

Step 21: Glassing: Remove the Edging Tape Before the Resin Full Cures

After about 3 or so hours remove the edging tape before the resin full cures. This will allow you to easy pull the tape off while it's still tacky. Make sure it's not still dripping and has solidified a bit. I had to have a sticky texture to it. This should result in a very clean line on the edge.

Step 22: Glassing the Other Side

I like to wait at least a day before I flip the board and glass the other side. You want to make sure the epoxy has cured hard with no tackiness or stick at all.

Step 23: Polishing and Minor Sanding

Once the board has fully cured this is the part where you put the finishing touches on the board. There are many different ways to polish and sand you board. I use this polisher/sander but a simple orbital sander works just fine also. I personally like to use a very find grit like 180 with my sander/polisher. Don't sand too much to the point where you get down to the foam core. I can only give so much direction here, it really is a trial and error process to sand.

You want to put on some safety glasses, gloves, wear a long sleeve shirt and get yourself a good breathing mask. Fiberglass and Epoxy dust is not good to breathe in, get in your eyes or even have touch your skin. I do this outside on my lawn if needed. Fiberglass dust itches bad so wear proper protection.

Sand out all the blemishes using different levels of grit until you've achived a matte/smooth finish.

If you've sanded too much and the fiberglass texture is showing or even the foam you can always go back and brush on epoxy over the blemished area. Just make sure to let it cure.

Step 24: Polishing Your Skimboard

After you've buffed both sides you might want to achieve a shiny coat. Sometimes you might want to brush on one more layer of epoxy to achieve this depending on the level of gloss you want. Putting another layer of epoxy will give it shine but will still need to be polished out to have smoothness.

To polish I suggest using this compound as well as this polishing kit which can work with an electric hand drill and or your polishing sander. You also need a polishing wax which you can find at your local auto store or you can buy surfboard polish like this.

Step 25: Last Step! Traction Pads

Traction pads are a must. They do exactly what they're supposed to...Give you grip on your board and more control . The best ones on the market in my opinion are the Zap skimboard brand.

Step 26: Final Word

Thanks for reading this tutorial on how to make an xps fiberglass foam skimboard. There are many ways to make skimboards and this way was one that worked for me. I created my board custom to myself because I needed a wider and taller board. It rides amazing and I actually came under budget. I wanted to spend under 400$ which is an average cost for one of these. I had many of the tools already so really my total cost was about $250.00 in materials and supplies. I went through about 3 different attempts at making this board until I finally got the process down. Attention to detail is crucial, and patience is second to that in priority. Don't rush. This board took me 3 months because of the learning process. Now I believe I can get this down to 4 days.

Above is the photo of my finished first board. I am currently working on a new board with the same dimensions but i'm adding improvements to the smoothness of the final glass coat. I'll be posting photos here as soon as it's done.

Thank you for reading!