# Equation for amount of resin needed

To all glassing pro's. I am new to Swaylock's ( I've got thick skin so let me have it) and have made and sold a couple boards ranging from 5'10 - 8'. All being the norm polyurethane/polyester glassed. I am currently going to start making EPS SUP's and haven't the faintest idea on how much epoxy I will be needing for lamination. I have never worked with epoxy which my research on that has already begun. As for now my question is if there is a equation to use to figure out how much epoxy resin needed for glassing. I'll be glassing first a 12' board 3 layers of 6oz. on deck and 2 layers 6oz. on bottom. I've heard 2 layers of 4oz. + 1 layer 6oz on deck is used often though. Any info on that also welcome. I am in the process of trying to round up an order for material and this is where I get stuck. I usually make polyurethane boards so epoxy is going to be a learning experience in its self. Any and all criticism/help is appreciated.

A good starting point is  a 50% to 50% fiberglass to epoxy ratio.    Or 1:1 by weight.

Lay all the glass you’re going to use for a side and weigh it after cutting the excess overhang back to the desired lap width.

The weight of glass should equal the same as the total amount of epoxy and hardener mixed.

You can go a fair bit less than this if you use a wet out table and or use a prepreg method of glass wet out.

Bear in mind three layers of 6oz. glass on a 12’ sup  deck is going to drink up a fair bit of epoxy no matter how you mix it.

If you’re doing EPS , I’d recommend sealing the foam prior to glassing, especially if wetting out the glass while it’s ontop of the foam core.

Stuff like cork and HD foam skins allow you to use less glass on boards like Sups and generally result in a stronger, and quite often  a lighter overall deck skin weight.      But that’s a different topic.

VH.

Hi bluefinsurf -

Segway Composites has a website detailing suggested glassing schedules for the various EPS densities.  Your foam density should be the first thing to figure out, then your glass weight/amount, then your resin amount.

Once you determine the weight and number of glass layers, multiply the total by 1-1.25 for your resin amount.  If your board is 12 feet long and you plan to use double 6 oz....  figure 8 yds (running length) of cloth X 6 oz = 48.  Multiply by 1 - 1.25 = 48 - 60 ozs of resin.

Any resin amount estimates based solely on length will likely get you in to trouble.  You have to be able to saturate all of your cloth regardless of board length.  Extra layers of cloth will require extra resin amounts.  If you have to ask, it's likely that you would be safer to start with a little extra and be able to squeegee it off than run short and risk fucking up your ratios trying to mix an extra batch in a hurry.  Dragging your resin around is likely to create froth and if you're glassing over color, you don't want that either.  A little too much isn't going to hurt.  Just get it out of the bucket pronto to prevent it from exotherming and kicking before you can get it on the board!

For your fill coat, use about what it would take to saturate one length of cloth...  I.E. 24 ounces.  Again, you can brush it out or squeegee some off if it seems like too much.  I usually use a heavy hand on the brush in the center of the board and kind of let it flow around the edges and overlaps.

Once you do it a time or two, you can tailor the amounts to fit your style.  These are just beginnner recommendations.  Someone else's 'standard' amount for a single layered shortboard definitely isn't going to cut it.

Maybe get a thermometer and a gram scale with at least a 5lb capacity.  Some paint stores sell calibrated mixing buckets - those work too.  Best to work with epoxy around 75 degrees and mix your ratios accurately.

Edit:  Sorry Vanhelsing.  Didn't see your post.  Similar recommendation though.

Thank you Johnmellor and Vanhelsing for the information. I was guessing around 2 gallons total for a 12' board for lam and filler coat. John thanks for the Segway comment. Checked it out and confirmed my thought about the double 4oz with single 6oz. on deck. Also I was going to use 1.5pound density for most SUP's but also was going to use 2.0lb. for my brothers rental boards to accomodate for dings and abuse they get for being rentals so the glassing schedule will change with the density.

Hey Bluefinsurf,

Last year, I built a 10’ x 31" SUP from 1.5# EPS and thinking along your lines, I kept track of my epoxy (mixed) usage for future reference. Bottom layup - 1 layer 4oz Innegra + 1 layer 6 oz e-cloth. I used a total of 36oz resin & hardener for lay-up and 12 oz. to hot coat. Top Lay-up - 2 full length layers of 6 oz. e-cloth + ~ 6’ of bamboo veneer (under standing area) + another 6’ piece of 6 oz. e-cloth. I used a total of 48oz of resin & hardener for lay-up and 16oz to hot coat.  While I did vac.bag my laminations, the board weighed about 19# after lay-up.

Hope this helps. Hopefully you can extrapolate from this up to the size of your board.

One last note. I recently completed a kitesurf board(which I’ll be posting here soon) and for the first time, I mixed my epoxy by weight at the suggestion of Wade @ Fiberglass Hawaii. I purchased a cheap digital scale from Harbor Freight and put it inside a clear freezer bag before using. Every mix came out consistent and hardened properly so I’m sold and will not go back to mixing by volume.

Cheers!

Hi Bluefinsurf -

Since you know the density of your foam and have access to the Segway recommendations, you're on the way.

I just did a single 6oz carbon layer on the bottom of a board I'm making.  Since I can't see what's going on under the fabric, I purposely overdid it a bit on resin amounts.  I lifted the overlaps and brushed resin on the underside of the rails.  I used my 1.25 X total cloth weight (untrimmed)formula and still ended up mixing a small batch of additional resin to touch up the laps.  WTF - I'm a hack.

I'm not that worried about saving every last ounce of weight.  I try to make sure I have good saturation before squeegeeing off the excess.  I ended up with some on the ground and some in my brush.  I try not to go overly heavy handed on the squeegee.  I did not have to do a cheater coat and I'm pretty certain I don't have any pin air under the carbon.

parthenonsurfer seems a bit on the light side, but in the ballpark as far as amounts.  Since he is vacuum bagging, it makes perfect sense.  Hand layups require a bit more resin.

[quote="\$1"]

To all glassing pro's. I am new to Swaylock's ( I've got thick skin so let me have it) and have made and sold a couple boards ranging from 5'10 - 8'. All being the norm polyurethane/polyester glassed. I am currently going to start making EPS SUP's and haven't the faintest idea on how much epoxy I will be needing for lamination. I have never worked with epoxy which my research on that has already begun. As for now my question is if there is a equation to use to figure out how much epoxy resin needed for glassing. I'll be glassing first a 12' board 3 layers of 6oz. on deck and 2 layers 6oz. on bottom. I've heard 2 layers of 4oz. + 1 layer 6oz on deck is used often though. Any info on that also welcome. I am in the process of trying to round up an order for material and this is where I get stuck. I usually make polyurethane boards so epoxy is going to be a learning experience in its self. Any and all criticism/help is appreciated.

[/quote]

You've got big balls to do your first Epoxy glass job on a 12 footer with 3 layers of 6oz cloth..........

Most SUP's are over 4" thick and more than 30" wide....Yeah, sure... go for it!!!!!!!

or...build a 5'10 fish with 1.75 EPS foam....and...glass that with Epoxy.

Better to learn how to work with EPS/Epoxy on something small.....then pull out the big guns later

...Stingray.....

and Many will disagree but I'm a big fan of Spackle ( DAP FAST AND FINAL).

"You've got big balls to do your first Epoxy glass job on a 12 footer with 3 layers of 6oz cloth.........."

As long as you use slow cure hardener and stagger your lap cuts you should be OK.  Trim the inner layer like a deck patch.  Trim the next layer at the rail apex, and the outer layer with a full overlap.  3 layers with full overlaps would definitely be a bitch.  It's the laps that'll give you trouble.

Watch your temperatures (glass during cooler temps for added working time) and use plenty of resin.  Glassing as temps are dropping is always a good idea to avoid outgassing.  A common problem with multiple layers is pin air between the layers.  Just don't get carried away with the squeegee and don't skimp on your resin amounts.  It will take longer for the resin to penetrate all the layers - lift a layer or two and pour some resin between layers if you choose.  It will soak in on it's own if you spread it around slowly and give it some time.

And yes, 3 layers WILL drink up some resin so don't be greedy with your resin amounts... pour it out on the center of the board and work outward from the puddle.  It will get hot and kick fast if left in the bucket too long.

"and Many will disagree but I'm a big fan of Spackle ( DAP FAST AND FINAL)."

Sealing the blank will keep it from drinking up even more resin, adding weight, and leaving behind pin air between the foam and glass.

Lol Im actually quite fond of my balls stingray. My favorite saying is “Go big or Go home” so I’m going to take the chance. I’m sure you’re right though about the practice board. If anything I might do a couple small practice jobs on some foam to get a sense on the epoxy. Thanks for the tips guys. This site is awesome.

I’ve never glassed a SUP, so I don’t know about amounts.
But I can advise you on stategy/technique…

I don’t like to use a wet out table… I do traditional hand lams… and I can tell you that when you do three layers of heavy cloth it can get tricky. But this is what I’ve had success with… If you lay out you cloth, fold up the laps, wet the foam from the apex down, then fold back down the laps, you’ll be sure to wet out the laps evenly when you tuck, with no dry spots. Also, be sure to spread out your resin EVENLY all over the flats, covering the entire surface, and let it soak in for a minute before you start working anything. Once the cloth has had a chance to drink up some resin, work it a bit. Not like poly, but give it a few firm passes with the spreader to get the air out and the resin in, pulling out much of the excess back into the bucket. Work slowly, and don’t froth it up. Then… re-pour what’s in the bucket back onto the flats, spreading it out evenly to re-saturate. Once spread out evenly, start pulling and tucking from stringer to rail.

The “tricks” are to work SLOWLY, and spreading EVENLY with the spreader at a low angle (not raking the glass with the edge). I can’t stress enough about how important the pour is… a gentle pour, with the spreader following the stream of resin, spreading it out EVENLY over the flats is the key to minimizing waste and not frothing up the resin. If you run short, quantity can be made up with a mini batch when you need it. You’re priority is wetting everything out well with three layers of cloth, and getting them tight and flat.

[quote="\$1"] Lol Im actually quite fond of my balls stingray. My favorite saying is "Go big or Go home" so I'm going to take the chance. I'm sure you're right though about the practice board. If anything I might do a couple small practice jobs on some foam to get a sense on the epoxy. Thanks for the tips guys. This site is awesome. [/quote]

Successfull people take risks......calculated risk......some go big and do good....some go big and fail...Surfers, surfboards, blanks, and Paddleboards are full of winners and losers........you have the skills...go for it!

Some people like Stingray are on the Long Term Plan.....small calculated risk...baby steps...Long term Success.......

I'm a big fan of John Mellor and NJ Surfer....I can give you links to some of my epoxy threads if you want them.....Your fiberglass layers are overkill in my world...Have fun,,,,report back here.........

Ray

http://www2.swaylocks.com/forums/epoxy-resin-and-colorlow-tech-step-step

http://www2.swaylocks.com/forums/random-photos-low-tech-lab

http://www2.swaylocks.com/forums/first-epoxy-glass-job-s

Ray I do want to be successful and do respect anybody’s input or criticsm that is given on here including yours. I just know that I learn better by just going for it. Especially something that big. Though it is a big risk and cost. Thats why I came on here to get tips/pointers by the experienced. Id love to hear your thoughts about the fiber layers. I was under the impression that since I will be making rental paddle boards that they should be heavier glassed due to peoples lack of respect for rental equipment. I know that for the boards that are for personal use and retail sale are glassed lighter. From what Segway shows, I should use two layers of 4oz. plus 1 layer of 6oz. for deck and a single 6 & 4 oz. for bottom on a 1.5lb. blank. I figured do that for retail boards and all 6oz. for rentals with 2lb blanks. But if thats too much for either then what would you suggest.

Hello Mr. Big,,,, no insults coming from the Stingray camp.......if we all agree there's no discussion.

Here on Swaylock's we're just a bunch of like minded people sitting around the camp fire. When you are ready to think with your Brain instead of your Bravado maybe you can follow my logic...Maybe I'm right...maybe I'm Left.......Most people I get into a debate with are building Space Ships.....you feel the need to build a BattleShip.

12 foot SUP built for a Rental Fleet. Most likely the SUP will never see open ocean. Good chance the Fleet is for a Bay or Lake. Even if the SUP goes into the Ocean there's a really good chance it will never ride waves. Who will rent these SUP's? Hot chicks in hot pants with lame muscle bound boy toys.....Where does the damage come from? Storage, transportation and the paddle.

No Hot Chick in her RIGHT MIND is going to carry a 12 foot SUP glassed with a 3x6 deck and a 2x6 bottom!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

add to that...Most SUP's have a full deck pad and the rider just stands in one place. No duck dives, no knee dents or heel dents or rail crushes from palms on duck dives.

Stingray

Ray I checked out your threads, good stuff bud. Like the board with the rainbow cut lap. Nice work. What would you recommend on the layers? 2x4oz. with a 6oz. patch on deck or just double 4oz. only? These boards will have a pad on them also. As for working with epoxy, other than being clean , the temps, and not over working, how much different is it from poly to work with? Some people say its not hard as long as you are calm, some say its a bitch. Then I’ve seen a post from Resin Research stating that as long as you follow their directions you’ll be good. Makes me dumb founded. Also whats the deal with tints and resin coloring causing problems? Most boards that I’ve seen that are epoxy are colored resin. Saw someone stat that colo Aring epoxy resin is a no no or is it just with hotcoat? Thanks

Hello Mr Big Blue Fin.

Update your user profile to include location. Why? A guy from San Marcos, California posted some awesome wood fins on Swaylock's. I contacted the guy and he lives less than 2 miles from my house. He made me a killer set of fins. Everyone loves those fins. We're working on our second deal. A Win Win for both parties. The guy's name is WBrame. Long term relationship building.....

Like I said before...I'm a big fan of JohnMellor and NJ Surfer...follow what they teach....

Here's my SUP story......I hate Stand Up Paddle boards in the line up....big kooks with brooms sweeping the line up and hogging waves.....SUP's out in the kelp bed or in the bay / lagoon are no problem. I own a 12' 6" Flat Water SUP. The blank was machine shaped by Ken at Segway Composites. I got a deal on the shaped blank because it was damaged. I glassed my 12-6 with one layer of 6oz on the bottom and one layer of 6oz on the top. The top also got a massive 6 oz deck patch that covers 2/3 of the board. The nose looks like a canoe. The underside of the nose has extra 6 oz cloth so the board can get "run Up" to the beach. The fin box is capped with 4 oz cloth.

What did I learn and what would I do different on the next SUP?  I'm talking about a 12' 6" Flat water board that will never see surf. No need for a deck patch. Just extra weight. No need to cap the fin box. We're paddling around the bay. No stress on the fin. No reason to make the board so massive. A 10 footer would do the trick.

Get it? Got it...good!        Stingray.....

For some reason this thing keeps saying that I'm in Hawaii. Not sure what you see as my location. I wish I lived in Hawaii. I'm in a little city called Venice,FL not much surf except for ground swells and hurricane seasons, and winter swells.

With SUP’s mix a batch of 24 oz for the bottom and start laminating one side of the bottom.  Laminate that whole side, stringer to rail, tuck and finish the laps.  If you have excess resin push that to the other side and begin to wet.  Now when you run out its pretty easy to estimate how much more you’ll need to finish.  Mix that amount and laminate the second side.  With epoxy you can do this no problem.  Using slow hardener you can even stop between batches, have a beer, answer a phone call, etc.  Really important though, as soon as you mix epoxy pour all of it on the flats and spread it around.  This will double your pot life.  Leave it in the bucket and it’ll kick your ass.

glass it!

Thanks fellas for the tips. There’s a 6 week wait on my eps blanks from US blanks here in Florida so when I start one I’ll post some pics. Greg Loehr are you in Florida warehouse these days or west side? Plan on making a trip to the Florida warehouse when I get my blanks to make a purchase and maybe to shoot the shit with the guys there for some tips also would love to pick your mind if you’re there.

I’m not there but Sam is.