Paddleboard Plans (.com) - How to Build a DIY SUP in One Day

I built a paddleboard from polyethylene foam, aluminum angles and bars and Gorilla Tape. The materials cost is about $200, but shipping the materials adds about another $50.  The paddleboard is 2 feet wide and 9 feet long.

 It's a flat water paddleboard, with a flat top and flat bottom. It took about an afternoon to build.  Scroll Down

The most common use was being used as a raft or float or platform by boys and girls of all ages for roughhousing. 

So easy a two-year-old can do it:

Used by seven to ten teenagers at once, which stressed the tape: 

 

 

Below is a view of the two feet by 8 feet aluminum frame assembled on the garage floor on scrap wood.  Unfortunately, the photography has a slight optical illusion that makes it look wider at one end then the other.  It's a rectangle. 

All the aluminum is 1/8 (.125) of an inch thick.  All of the angles are equal-leg and 1.5 (one and a half) inches by 1.5 inches.  The two bars are two inches wide.  The two sides, laid out first on the bottom, are eight feet long, 1.5 inch by 1.5 inch angles. The ends are the same 1.5 by 1.5 inch angles and two feet long. The center angles are the same same 1.5 by 1.5 inches by two feet long.

In total, there are six pieces of aluminum that span from side to side on top of the two sides.  The front and back are symmetrical with three pieces of aluminum spanning each half. On each half, there is a front and end angle.  The flat bars are 16 inches from the center. I placed the flat bars only 16 inches from the center because the standing person's weight will normally be around the center. 

The six spanning pieces of aluminum each require a stainless steel screw, nut and two washers on each end, for a subtotal of 12 screws.  There is also one screw used, shown near my toe in the picture below, to screw the two center angles together forming a strong center beam.  This is a total of 13 screws, 13 nuts and 26 washers.  Given that you might lose a screw, nut or washer, I would buy a few extra.

 

 

This is another view of the center with the flat bar shown 16 inches from the center.  I used two-inch thick scrap wood to avoid drilling into the floor.  Place the scrap wood directly under the hole you are drilling.  Scrap pieces of 2 by 4 wood should work, but I had larger pieces of wood.  After drilling a hole, install and hand-tighten a screw, nut and two washers to hold it in place. A second person to watch and hold the angles while you are drilling is very helpful. The order of installing the angles and bars does not have to be in a specific order, but doing the two end angles first to form a rectangle, then the two center angles, and the two bars last works. 

 

This a view of an corner.  It's difficult to see, but that is a nut and washer around the screw facing up or into the interior.  On the exterior bottom, for a smooth exterior, you want the smooth head of the screw and a washer. Because of the small metal shards from drilling, constructing over carpeting or a good wood floor is not recommended.  Also try to wipe any metal bits off your shoes before walking into your house. Use the usual safety precautions when power drilling metal. 

 

This is what the foam looks like out of the box.  It's 4.5 feet by a little over 2 feet.  It's really a 9-foot long plank cut in two to save on shipping.  Also for safety, having two separate pieces means the aluminum will still float if the tape fails on one half. It's NOT exactly 24 inches wide.  The foam pieces I that I received were nearly 25 inches wide.  Make sure you space the aluminum to tightly fit the exact foam size you get, and do not assume it will be twenty-four inches exactly.  A second person/helper is very useful in holding the foam and angles in position so that the drilling is spaced correctly.  The angle edges will not be exactly flush flush with the sides if the foam is over 24 inches wide.   

 

This is what the foam looks like when stepped on by a 150 pound person. It's the same foam that is used in sea/pool noodles and some floats, but it's a higher density and strength.  

 

After the frame is bolted and tightened with a wrench, place the foam in one piece at a time.  If there is a bad end, such as the "15" in marker, put the bad end towards the center.

 

If the foam is not cut perfectly at 90 degrees or the angles are not at exactly 90 degrees, you may need to trim the foam with a saw and/or utility knife. The bottom of the foam needs to be trimmed slightly as shown in the picture below so that the top can be flush with each other and the bottom go over the 1/8 inch thick angle.

 

The next step is tricky since you have to cut about a one inch slot in the foam to fit around the front (and later rear) 1.5 inch angle.  I apologize for not taking a photo of the process, but I was worried about cutting myself and incorrectly cutting the foam. UNLIKE the picture below, you cut the foam BEFORE taping it together.  This takes two people: one person to hold the foam against the center angle tightly and another person to hold a very sharp, razor sharp knife (I used a linoleum blade/knife) and cut all the way down the foam.  Box cutter blades are sharp, but not long enough.  I bought a longer linoleum blade at Lowes for $2.99 and put that in my box cutter. Place the knife as shown in red in the picture below against the angle.  Move the knife down the angle all the way to the bottom cutting about a one inch deep cut.  After making the cut, place the frame back on the ground and press the foam back and on the angle.  You will need to kneel on the foam to press it all the way down on the angle and screws.  Repeat this process with the other piece of foam on the other side.  

 

After pressing the foam into the frame with your body weight, tape the foam in place with THREE inch wide Gorilla Tape.  I hoped to find some glue that would work for polyethylene foam and aluminum, but after weeks of searching online (don't believe every "glues everything" glue advertisement) and a couple of failed glue experiments, I gave up.  It's not a perfect solution, but it works.  If the Gorilla Tape does not last forever, it's easy to reapply.  Pull the tape as tight as you can:

 

Use a putty knife to push and fold the tape around the angle for a good grip:

There are three strips of tape on each half and an overlapping strip of tape in the center for a total of seven strips of tape.  The center tape overlaps two strips of tape to keep the foam together: 

Top View:  The top is entirely soft foam and soft tape. 

 

Bottom View.  The center tape overlaps itself over the aluminum. 

 

It weighs only 25 pounds and easy to carry:

UPDATE AFTER ONE YEAR OF USE:  Due to large groups of up to a dozen kids playing on it at once, often trying to tip each other off as part of some game such as "King of the Board," the stresses on the paddleboard were larger than I anticipated and the Gorilla Tape at the ends failed.  I am going to double or triple tape, going all the way around on the ends next year.  I did try to repair it with white Hurricane (brand) Tape, but Hurricane Tape did not work as well as Gorilla Tape.  The foam and the aluminum held up well.

Assistant Board Builder and Board Tester:

 

Fits in back of small Honda SUV with window up and with front seat forward. This reduces the number of seats for people.  Also not all SUV's let you open the back window. 

We were debating how to shape the front and rear to make it streamlined, but we did not reach a decision and did nothing yet.  It would be easy to carve the front and rear foam that extends past the aluminum into a carved shape with a linoleum knife or saw, but making the foam, or anything, thinner does reduce its strength.  Untested possibilities are cutting a 45 or 60 degree angle strait across (classic wood punt design) or cutting circular curves on each side tapering to a 1-foot wide front.

 

Paddle: 

Online, there are numerous options for buying a paddle board paddle or making one.  Paddle board paddles are longer and need to be stronger than canoe paddles, so you just can't use a four-foot, $10 canoe paddle from Walmart.  I had a spare 18 inch plastic paddle blade from an old inflatable kayak, so I built the below paddle with a 5 foot wood handle ($5 at Home Depot in garden section) and bicycle "cork" (foam) handlebar tape. 

 

Materials: 

 

This is the foam:  From  http://www.foamforyou.com/polyethylene_foam.htm

With 20:20 hindsight, I might have paid an extra $10 for black or blue foam so the tape would not look as obvious.  But many people did find the homemade tape look "cool" and "awesome." 

This is the aluminum:

Buy your aluminum at OnlineMetals.com.

Ordering an angle of Aluminum is not simple.  You can't just say, "Give me a piece of aluminum."  You have to order the right LENGTH, THICKNESS, (.125 or 1/8), LEG DEPTH (1.5 inches) and type of aluminum (6061).

Go to Online Metals, (opens in new widow so you can view this page and new page) click on ALUMINUM, than on ANGLES, then on 6061, then on 1.5 by 1.5 inches with .125 thickness, and you should end up at a page like the one below. Select EIGHT foot length and add 2 to your shopping basket (cart) for the two sides of the board.   Check the items I have underlined in read.  

At Online Metals, (opens in new widow so you can view this page and new page) click on ALUMINUM, than on ANGLES, then on 6061, then on 1.5 by 1.5 inches with .125 thickness, and you should end up at a page like the one below. Select TWO foot length and add 4 to your shopping basket (cart).   Check the items I have underlined in read.  OPTIONAL: If you have a good saw and don't mind cutting aluminum, it's possible to save a few dollars by ordering another EIGHT foot length (same as above/the sides) and cutting the eight-foot length into four two-foot sections with three cuts, but be warned that cutting aluminum with a hacksaw takes some effort and time.

At Online Metals, (opens in new widow so you can view this page and new page) click on ALUMINUM, than on FLAT BARS, then on 6061, then on 2 inch wide with .125 thickness, and you should end up at a page like the one below. Select TWO foot length and add 2 to your shopping basket (cart).   Check the items I have underlined in read. 

 

These are the STAINLESS STEEL screws, nuts and washers I bought on eBay from someone named "CedarCliff88."  I bought far more than I needed.  Some stainless steel screws and nuts are available in local hardware stores, but it's hit or miss if they have enough (13) in stock.  You do not need a "button head" screw, but whatever screw you buy should have a smooth top so that you don't scratch your hand on it when carrying the paddleboard.  

 

I tried using my regular "wood" drill bits that I had, but I had difficulty starting the holes.  The drill bit wandered a bit before starting a hole.  I went to Home Depot and bought a "Pilot Point" DeWalt drill bit that worked better.  A few times the 3/16 hole was a tad bit small for the number 10 screws, so I had to widen the hole by redrilling and wiggling the drill.  Also I started using a cordless drill, but drilling aluminum takes more power than drilling wood, and my battery ran out of power, which is frustrating if you want to finish building in an afternoon with a kid.  If you only have a cordless drill, you might run down the battery before finishing.  Recharge your batteries before starting and hope the charge lasts, or find a plug-in drill. 

 

Use THREE inch (technically 2.88 inch) Gorilla Tape, which is wider and harder to find than the two inch standard "duct-tape" width.  The tape is literally holding the foam on, and each half has about 90 pound of buoyancy force pushing up on it, so don't try to get by with narrow two inch tape.  If anything, you may need to double the tape in the front making it six inches wide.  I found that only Lowe's Hardware store carried the three inch tape locally at about $15 for 30 yards, which is about about four times the length that you need (seven strips of about one yard), so you have plenty to spare and reapply in the future if needed or to increase the number of strips.  

 

Design Notes:

The design was inspired more by Thames (river) Punt boats than by surfboards.  Wikipedia has an article on Thames Punts which were used in England for centuries for stand up boating.

The static load of a 180 pound person is 20 pounds pushing up on each foot of the nine foot length.  

The buoyancy is 9 feet times 2 feet times 1/3 feet (4 inches thick) times 62.4 (weight of cubic foot of water displaced) = 375 pounds.  Since, the board itself weights 25 pounds, there is 350 pounds of buoyancy left.   We had three kids on it weighing a total of 250 pounds and it looked OK.  The photo at top has a 180 pound person on it. You need 100 pounds or so of reserve buoyancy or else unless perfectly centered standing, one side or the other will sink.  The board is not recommended for people over 250 pounds.  For people weighing 200 to 250 pound, the board will be lower in the water and harder to control.  For people weighing over 180 pounds, doubling up the tape to 5 inches wide (overlapping 1 inch)  may be needed since the buoyancy provided by the foam (equal to the weight of the person) is transferred to the aluminum by the tape.   Trimming foam from the front and/or rear to streamline the board will reduce buoyancy by 62.4 pounds for every cubic foot of foam removed.  

While it's only 24 inches wide, the rectangular design makes it very stable in terms of standing up on it.  Without and surfing or SUP experience, I was able to make it across that lake several times without falling once.   See this YouTube video for stand up paddleboard instructions.  Without fins it's not easy to keep in a straight line without switching the paddle from side-to-side.  I was hoping that the rectangular sides would keep the board moving straight.  

The long term durability of the foam and tape is unknown.  The foam is not ultraviolet light (UV) protected.  Do not store in direct sunlight.  Do not store uncovered outside.

Safety: 

Everyone eventually falls into the water.  Paddle boarding when the water is too cold to swim in can result in hypothermia or death.  Do not go beyond your ability to swim, without the paddleboard, back to safety.  Paddle boarding in rocky rapids is extremely dangerous since one may fall when the board hits a rock; falling on a rock in the water can result in injury or death.  If you really want to paddleboard in rapids, research and use safety precautions. 

Especially outside of swim or surf areas and in navigable waters, the Coast Guard and some states may regulate paddleboards the same way they regulate canoes and kayaks and require life preservers and possibly registration.

Press Release: How To Build a Stand Up Paddleboard in One Day

Free, step-by-step plans that show how to build a stand up paddle board are on a new website PaddleBoardPlans.com.

Building a stand up paddleboard is both fun to build and fun to use on the water. Building a paddleboard, just like building any small boat, can be an educational parent-child activity. The paddleboard is very easy to build since it consists of only eight pieces of aluminum, two pieces of foam and thirteen nut/screw/washer sets. The only power tool required is a power drill. It can be built in an afternoon. For the complete plans, visit http://www.paddleboardplans.com 

Stand up paddleboarding is easy. Unlike a windsurfer that requires wind and time to master windsurfing, a paddleboard can be used wherever there is water. Unlike a surfboard that requires an ocean with waves and time to master surfing, a paddleboard can be used on flat water. If you can stand, you can stand up paddleboard.

The paddleboard has a soft, flat foam top that does not hurt if fallen on. The flat top also lets one play on it, lay on it, or do yoga on it. Compared to larger boats, canoes or kayaks, a paddleboard is lighter and easier to transport and store. The complete plans are free on http://www.paddleboardplans.com  

“The grandchildren played on the paddleboard for four hours straight. They were unable to tip each other off it.” “Most Awesome.” – grandchild.

 

(c) 2012 Steve Baba.  This website with DIY (do it yourself) free boat plans is supported by affiliate programs from Online Metals and Amazon.com.

 

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