I have all the gear ready to fibreglass my first board. I just want to get a few things clear before I start.
The board is a 5’11" x 22" x 2 5/8" EPS fish. I intend on doing 2 x 6 ounce top and 1 x 6 ounce bottom.
How many litres of Epoxy resin should I be mixing up for each layer?
Should I mix up small batches in cups and do a little at a time or should I do one big batch to do the whole side?
I have applied a layer of epoxy to seal my wooden fins as a first step to using epoxy.
I didn’t really have time to sit around watching it set but it seemed to take a long time to harden. It was still movable over an hour later. At first I thought I’d stuffed the mix but by the next morning it had hardened nicely.
Is it ok to laminate one side of the board and then wait until the next day to flip it and do the other side?
Or should I try and flip it within a certain timeframe?
I have been given a roll of fibreglass cloth that is super thick. I have no idea of what weight it is but it is heavy.
I was thinking I could use this cloth do do a fin panel for a single fin I have planned for in the future.
When laying up a fin panel with epoxy can I lay up the panel in one go?
Doing about 5 layers at a time but the whole thing at once.
Or should I do a few separate layers let them harden then lay them up together?
I have read here that if you use a very thick layer of epoxy that it can get very hot and even overheat and crack.
Is this correct or am I misreading this.
Thanks for the help guys. I’ve had a bit of a look in the archives but I didn’t find what I was after. Maybe some guys have some fresh thoughts anyway.
How many litres of Epoxy resin should I be mixing up for each layer?
Should I mix up small batches in cups and do a little at a time or should I do one big batch to do the whole side?
Mix up a 300ml batch and use that, should cover most of it, as you said it took a while to set, don’t rush, you’ve got plenty of time, use a 3-4" wide brush or roller…
Is it ok to laminate one side of the board and then wait until the next day to flip it and do the other side?
Or should I try and flip it within a certain timeframe?
Again, no rush, flip it over the next day…
When laying up a fin panel with epoxy can I lay up the panel in one go?
Doing about 5 layers at a time but the whole thing at once.
Or should I do a few separate layers let them harden then lay them up together?
Do 5 layers and wet that out, put the next 5 on and wet out etc until its thick enough…
WARNING, epoxy sticks to everything, even bricks and glass, lay it up on a plyable plastic surface like thick black plastic, when you have finished laying it up, put plastic over the top and weigh it down with a heavy weight, helps to infuse the resin into the glass and eliminates bubbles…
Hi there, lots of questions… I’ll answer best I can.
For a board that size, 250 - 300ml for each side when laminating. Maybe go on the lenient side and use 300ml as it is your first and you’ll probably get a bit on the floor
A little at a time will probably get frustrating as you’ll have sticky hands (use gloves of course) by the time you’ve used the first batch. Maybe get a second batch ready (say 50ml) and have the hardener for that quantity ready in a separate cup so that if you run out and need a little more, you don’t need to stuff around with measuring cups etc.
Yes depending on your hardener, epoxy will take longer to harden than Polyester resin… this works to your advantage as a first timer as you have more time to get the job right. Read the instructions. It should say how long for pot life (typically how long you have to work with it before it gells) and how long for a full cure.
Yes, take your time… laminate 1 side. Wait 24 hours, flip it and do the other. Don’t flip it when it isn’t cured - you won’t like the way the board will stick to your racks. Compared to Polyester resin, Epoxy sticks to everything… I’ve got a laminating table I use to laminate fins… with Poly resin ,I can leave it on the table for a day and peel it off easily. With epoxy, as soon as that resin is cured, there is much heartache separating a fin from the laminating table. Use a thick plastic sheet to avoid the pain.
Yes, laying up in 1 go could work depending on how thich you fin is… maybe safer to do it over a few steps as you suggest.
Yes epoxy can get pretty hot and the more resin, the hotter it gets. (i.e. you’re mixing bucket can get quite hot if you are taking a while to empty it onto the board). Maybe the 5 layers at a time is safest for you.
I like answer number 2. I can just see myself, sticky epoxy everywhere trying to measure out more cups. I’m not really known for my neatness thats one of the reasons why this is going to be a challange.
I have pump tops for the resin and hardener so that makes it a bit easier to measure the correct amount.
The slow curing of epoxy is one of the reasons i’m going with epoxy as I have had a few disasters with faster curing of polyester.
One of the main reasons I’m using epoxy is the lack of smell. I live in an apartment and I’m doing this in the garage which is under the building. If I was using polyester I think I would be kicked out due to the smell.
With measurement, I think you’ll still be safer using a measuring device such as a cup as it’s easy to get pumps wrong and only get say a half pump. Epoxy is more critical to get the mix of resin to hardener right than Polyester. Poly will just kick faster or slower so long as you keep the mix within a certain range. Epoxy can be problematic if you get the mix wrong (slightly out is ok). Putting in too much hardener for epoxy can cause the resin to not cure properly… different to Poly where it will just cure quicker.
Also, use separate measuring cups / devices to measure resin and hardener so that you don’t get left overs from the resin stuffing up your qauntity when pouring the hardener.
I use a fair bit less Epoxy than I do Poly… but that said, I don’t do much Poly so my technique might just be getting better.
Someone here may have a more scientific opinion than I!
I’m using West Systems epoxy. I get it from RF Saint Gobain in North Melbourne. Find a local retailer in your area though as it’s available around Aust. (not sure where you are)
I’m not sure on whether we mere mortals can get RR in Aus. Try calling the Firewire guys as I beleive they are using it but not sure?
is 300mls the same as 300gms ? [epoxy was weighed , polyester was mls , from memory , last time i used both .
again , from memory , i used 800 mls of polyester resin for the deck [2 layers of 5oz flatweave cloth] , the last time i did a 5’11 fish . this would be different to the 300mls / ?gms of epoxy , i’m thinking …
hope this helps ?
on the fin panel q: i have mainly done polyester resin fin panels , but watched hicksy lay up an epoxy one once [and spent a 'good half hour whacking the glass off it with a hammer , when it had set . true story]
cheers
ben
[if you have somewhere / one else you can go to for doing fins , polyester is good for laying up panels if you want to work on a few fins and have them cut out and foiled quicker .
just provide lots of ventilation , and also wear lots of protection …
When laying up a fin panel with epoxy can I lay up the panel in one go?
Doing about 5 layers at a time but the whole thing at once.
Or should I do a few separate layers let them harden then lay them up together?
I have read here that if you use a very thick layer of epoxy that it can get very hot and even overheat and crack.
Is this correct or am I misreading this.
Never had a problem. I do 5 layers at a time, pour epoxy over layers, spread it, roll it. Do the entire 6"x24" layup in about 20 minutes and make three fin sets from it.
I had leftover kitchen formica counter from a remodel. Tape wax paper to the formica, the epoxy wouldn’t stick to either. Always thought the formica worked better than glass anyway.
The epoxy gets hot in the pot, not in the layup, at least not noticeably. The cure rate is temperature dependent, you can always cool it down. I always let it cure overnight before foiling anyway, one of the downsides. You can always do the poly panels quick and be foiling an hour later. Maybe if you are not using RR epoxy it could go off faster…
Thanks for the replies guys. looks like my best bet is to order it online but i will talk to a few more people locally to see if i can find some around here.
is 300mls the same as 300gms ? [epoxy was weighed , polyester was mls , from memory , last time i used both .
No 300 ml is not the same as 300 gms. If you get the specific weight of the epoxy you are using…probably could get it from the manufacturer and then a few quick caluculations and you can caluculate the weight of your compounds you need. The best way to measure out epoxy is to use the specific weights and caluculate the amount of epoxy that you want. Weight it and weigh your resin. This will be the most accurate way to get the ration correct and in turn have your epoxy set perfectly. If anyone needs help with this just pm me. I am a chem student…thats how i know.
