My 12'6" splash mold process.... here we go.

[surfcowboy]

One good tip for the table top. Lightly glue down a thin sheet of mdf. Great work surface and you can replace it later if it gets scuffed up. Fast and easy smooth finish.

That board is a nightmare. I can't/can believe that it's that wacky.

[bef]

Making progress, at least I am past Bondo on a SUP!  Sanded the board again and got it pretty flat to the point of a thinner filler.  Sanded that down this morning at put a quick coat of primer over that to show all the places I need to fill with spot putty.  It is now at least flat enough to mold it.  If my feet didn't mind it before, anything I do from this point will just make it better.  At least the mold will be plenty flat where the pad goes.  Patched the nose up with epoxy and 3m spheres also.  Would like to be molding it by next week if possible.  16 days I go to Tennessee for a long weekend, would be nice to let the mold cure for that time to split it when I get back.

Cowboy, it is product quality like this that gives me hope on this project.  While I am not hoping to replicate Naish quality here, I figure how hard can it be to do better than what basically cost me $700 to my door, 40 pounds and poor quality?  I think I could lay up a 40 pound polyester board that would be stronger.

Might be an interesting challenge....  I figure about 50-55 square feet on this board.  A light layer of gelcoat and a layer of 1.5 oz matt would push 20-22 pounds.  That is about 1.5 gallons of resin, or 13 pounds, for 6 yards of matt (5 pounds).  Throw a second layer down under the middle section, some stringers...  Get it up to 40 pounds, it would be way strong.  Weather and sun impervious.  Cost would be about about $100 to $150.  Not my goal, but I will try it.  Would be a good cheap way to test out the molds....

Gotta have goals....

Brian

[SUPflorida]

Brian...you obviously know your way around this mold process...would you really consider using mat for the finished product? Come on...the mold certainly...the board itself? Say it isn't so...

[bef]

Brian...you obviously know your way around this mold process...would you really consider using mat for the finished product? Come on...the mold certainly...the board itself? Say it isn't so...

Why not?  with the quality of my original board in question, I really need six of these for the family.  Those I still see as epoxy/glass versions.  Need one as a gift for a family friend for her pond, so it will get left outside.  A polyester version might work as that seeing how it will be used as a swim raft by the kids, maybe even left floating in the pond a time or two.  Or maybe a polyester one is the one that we mount a modified and water cooled zenoah two stroke in.  maybe the one that gets a bike bolted to the top that is coupled to a water wheel....  We will do so many odd projects with these things that I will consider the board as disposable, I do not discount anything at this point.  How much fun would you let kids have with a board that only cost you $150 to make knowing they are learning?  That is some cheap experimentation and schooling right there.

I see a board with a bike frame attached to it that the output goes to a 90 gearbox driving a prop.  A rudder hooked up to cables to the handle bars.  Maybe some outriggers that allow you to bank into the turns.....  Could be a new sport. LOL!  A Sit up peddle Board!  Call it a SUP for short.  Wait, that is already taken.... dang!

Brian

[PonoBill]

Find a used Hobie Kayak power unit--much more efficient and easy to fit. I've considered fitting one to a SUP with pull rods like a Nordic track.

[bef]

Find a used Hobie Kayak power unit--much more efficient and easy to fit. I've considered fitting one to a SUP with pull rods like a Nordic track.

That would be interesting, those Hobie power units are neat.  Remember looking at one a year or so ago just before I decided to get into SUP.  I am sold on the SUP, but my kids...  well, you never know what they might try.  Hard to imagine what I would have been like as a kid if I had all this cool stuff back then.  3D printer sitting in the garage, CAD, mill, lathe, etc.....  Good grief!  I probably wouldn't have made it through high school.  Would have been too distracted.

[bef]

Starting to look like a paddle board again....  Top is smooth enough.  Hitting it with 600 grit is the next step tomorrow.  Hit a snag today, grabbed some 220 grit wet/dry paper and after startin sanding, realized it was NOT wet dry!  I hate it when black sand paper is not wet/dry, catches me off gaurd.  Cleaned it up, let it dry and then finished it off so I could hit it with another coat of primer.  600 and going to try gloss white before the wax.

Nose job turned out decent, not a glaring defect anymore.  You can still feel flaws in the surface when you run your hand over it, but it will have to be good enough.  Much of it will be covered by the deck pad anyways (or hatches and windows).

[bef]

So I got the top of it wet sanded out.  I took off the old fence pieces which I was using as paint shields for the mold fence.  Removed the masking tape from the mold halves joint.  Cleaned up the fiberglass fence.  Wet sanded out the paint line where the tape was protecting the mold joint and then prepped it.  Filled the vent plug with tape and then stuffed with clay.  The handle I filled in with clay and smoothed it out the best I could.  The rear deck plug for leash attachment was also filled in with clay and smoothed out.

Several coats of wax were put on and buffed out, looked shiney!  Applied a nice smooth layer of PVA mold release and let it dry.  On the 14th I applied the tooling gelcoat with a 6" short nap roller.  Actually seemed to work pretty good, we will see here next week though.  That afternoon I applied one layer of 1.5 oz mat (14 oz per sq. yard).  The next day I got another layer on the whole thing and two on the fence.  Friday night I got a second layer on the top main portion of the board.  So that set it with two good consistent layers.  Between Monday through today I applied at least another 3 layer of mat and also some reinforcing ribs similar to what I did on the other side.  The box down each rail is 8' long and covered in three layers of the 1.5 oz matt.  The 1/2" thick x 3" ribs on the deck are also covered in 3-4 layers of matt.  Done!

It is now ready to take a saw and trim the fence down to the 4" width that I want.  Then I will hit that with a belt sander to round it off and smooth it out further to dress it up.  I need to drill a bunch of 1/4" holes through the flange for bolting it together if I do not use a bunch of clamps.  If I go bolts, I will glue threaded steel parts onto the bottom half so bolting the halves together will go quickly with a drill and 7/16 nut driver.  The outside of the two mold halves will have to be touched up a bit for future vacuum bagging in a large tube, otherwise some of the rougher glass spots or sharp bumps will tear / puncture the bag.  The end of the square tubes on the sides of the mold will be blended in and smoothed out with some bondo.  Will have to leave some small holes so the tubes can vent during bagging, do not want to create a pressure chamber that might distort or damage the mold.  Not sure if it would matter but easy to prevent.

So next week I will probably finish trimming the edges and pop it apart!  Exciting!

Picture of the finished mold, somewhere in there is my paddle board!

[supuk]

All looks very familiar! I would just go for a tape down bag? I wanted to use a tube but unless you have a clever way of supporting the mold trying to get the bag over it when you will probably be struggling to lift it will not be easy however if you can it would save a little wastage and need for gum tape. I'm hoping to start a new mould myself soon for a 14' but first I think I'm going to have to build a bigger workshop! I think planning for having some lifting points like sic use for a pulley system would be well worth it.

[bef]

Guess I also need to glass some pieces of rope into each end so I have lifting points to help handle the molds.  Moving them would be easier and I could lift them like SIC did in their video.

Now to recap what I have in it:  The resin usage should be close.  I think I had some left over from my Hydrodyne project, not sure if it was an extra gallon or half a gallon.  I also used less mat than I estimated.  Thought I would use 70% of what I purchased, only used about 45% of it.  The 50" glass is also 39% wider than the standard yard.

Material usage:
Orange Tooling gelcoat:  I bought two gallons, still have 1/2 gallon left
Polyester Resin: I bought 16 gallons, have 3.75 left so I figure I used about 13 gallons total with the extra I had from before.
Glass mat, 1.5 oz x 50" wide: Bought a full roll, about 92 yards and 114 pounds.  Still have over 60 pounds left.  So used just over 50 pounds of glass.

Weight:  1.5 gallons gelcoat + 13 gallons resin + 50 pounds of glass = about 180 pounds in the two mold halves.

I already had rollers, gloves, protective coats, brushes, acetone, towels and such.  Went through less than a gallon of bondo, but did use a few of the spot putty tubes.  Lots of sand paper.  Just under a quart of PVA, small amount of wax.  My list says I spent just over $1,000 on this so far and I have over $300 of supplies left.  So about $700 for the molds, I already had some stuff, probably closer to $750 at the end.  And I still do not have a board......

Unless there is something wrong with you (like me), DO NOT DO THIS TYPE OF PROJECT!!!!! 

[bef]

....I wanted to use a tube but unless you have a clever way of supporting the mold trying to get the bag over it when you will probably be struggling to lift it will not be easy however if you can it would save a little wastage and need for gum tape......

yeah, thinking about that.  With the mold sitting on my cart, it is supported by two front poles and two rear poles, about 6' apart so 3.5' hanging off each end.  (almost 2 meters apart and 1 meter hanging off each end for the other 90% of the world.... LOL).  I can put the bag over the end of the mold hanging off and bunch it up next to the support rods.  Then just lift up that bagged end and set a 2x4 under it or use a sling on the pulley system to hold that end up.  That allows me to advance the bag under the first set of legs.  Once done there, set it back down and repeat the process on the rear.  Prop it up, advance the bag, drop it down, pull over end.  We will see.  With glass in it you are talking over 100 pounds for each half (45 kg).  Still haven't weighed them, so not sure if my weight calculation is correct.

Brian

[supuk]

Yea that's what I do when I do my boards you have to be so carfull not to nick the bag, I can only just pick up one end of my mould so there was no chance of geting a bag over it on my own it would need a minimum of two if not three people. When do you hope to lay up the first one? Any ideas on how you are going to jig up a finbox inside the mold? On mine I ended up routing it in after as I was in a rush but real it should be done all inside so once it comes out all you may have to do is route the opening geting them in stright is going to be the tricky part!

[bef]

Board construction:  This is my idea for what to try first.  I took into account that I weigh in at over 260 pounds and the board will be used for everyday flat water use.  So it has to be strong and no racing!
I am going to start with a small middle section just to try, about 2-3 feet long as a test.  But I hope this test will prove out acceptable for what I try first.
First thing will be to lay up two pieces on the original plug about 2" wide the full length of each side to form the internal flange.
Bottom will be laid up with two layers of 6.5 oz glass and epoxy.  ¾" EPS will be put down in the middle 8' of the board.  I figure at that point it will be vacuum bagged mostly to compress everything and remove air bubbles.  Then the core edges will be sanded down to help the glass slope in.  At this point, the core will have one layer of 6.5 oz glass put over it.  Depending on how the test layup goes, I figure I will have to add a couple layers of glass to the curved rails to strengthen them.  The stringers should take the main load though.  After that, the internal flange will be attached to the bottom shell.
The top will have one layer of 6.5 oz glass and epoxy put down.  The standing area is about 21" wide x 6' long, so due to my weight I am going to try a thin plywood as a core.  I will see what I can find at the store.  Then another layer  of glass over that.  Depending on my test section, I will see how much more the rails need for strength.
The stringers will be 8 to 9' long.  I am going to trim a 2x6 down to fit the profile between the deck and bottom once glassed.  To the top side, I will attach a strip of plywood 5.5" wide and seal it up.  I can then lay up a U shaped stringer with a 2" flange on either side of the top.  This can be popped off the form and filled with expanding foam, then trimmed flush.  The two stringers can be epoxied into the bottom section of the hull. 

[bef]

At this point, it will be time to join the halves.  The epoxy slurry will be made up and spread on the flange and the inside of the top deck.  I figure I will suspend the deck mold over the bottom mold.  At this point, I am thinking I mix a bit of expanding foam, poor a strip along the top of both stringers and drop the top deck into place.  Clamp it together and let it cure.  The expanding foam will fill the small gap between the deck core and the stringer – hopefully!
The handle, fin box and any plugs should already be in the board at this point, but I will cover that in a later thread. 

[bef]

Took a scroll saw and trimmed the flanges back.  Didn't go as neat as I planned in my mind.  I had what I thought was plenty of blades, but cutting up to 3/8" of glass will dull them really fast which makes them want to walk all over!  Still, got it trimmed up and then hit the edges with a belt sander to remove the nasty parts.  Ready for splitting...

Wow, for a large mold that came apart really easy.  Really really easy.  I have to attribute that to no framework on the mold to prevent twisting.  A wood wedge in the front, one more about a foot back and the front released!  Then just worked all the way around until it was seperated.  Bottom mold came off the board, board stayed with the deck mold. 

Had someone hold the front of the board down and I pressed down on the back of the deck mold untill I got a wood wedge under it.  A few tugs and the board popped out of the mold.  The clay even pulled out of the board and stayed with the mold.

Only thing that went wrong was a little bit of primer came off the vertical area of the nose.  No gelcoat on the board anywhere, which is the important one.  So now time to start washing them down and see if they need a touch of wet sanding.  I am definitely happy with how they turned out!  Gotta admit, that is a lot of mold surface for under $700 in materials.  And they are heavy!  Wow.  Definitely need lifting points.  Not the best molds I have ever built, but they are nice enough for what I need.