RDM,
Thanks for that. Any yellowing or brittleness with the UV shielded bote-cote over time?
As for the baking… 
I’ll be aiming for resins that cure bewlow about 40C initially. Tho I will be building a thermostat controlled “oven” in the near future, based on wood-drying ovens I have constructed before (simple, cheap and effective).
Thanks again,
-doug
Hey bluejuice!
Thanks for that. Is the non-yellowing hardener you mentioned also UV shielded?
cheers!
-doug
Doug,
nothing so far but it’s only been finished for a couple of months now and has not even seen a full summer yet. The yellowing may be hard for me to pick anyway as I didn’t paint my blue foam blank white or tint/colour the lamination. So it just may turn green instead.
Cheers
Rohan
Doug Not sure about that they say it’s UV resistant. Look for their web site via google.
Bert, when you will be in Europe, will you go to France? If so, will you have some of your surfboards on display somewhere? I’d be extremely interested to see your work and talk to you, and see how far back I am…just figuring out how good sandwich construction is… made a numerical foam cutting machine for cutting EPS blanks. I know the surfburger boards had a special Eurosima prize, well done!
News on the NZ ATL vs Oz ATL thing.
According to both parties they are sister companies and most of their products are produced by/available from both of them. Often under slightly different names, but normally with the same number scheme.
Unfortunately the 280TX product is not one of the products both companies supply 
The NZ tech guy says “The 280 is a more reactive form of 246TX and has a sherter pot life but correspondingly requires very little post cure” . And that neither contains UV blockers. Seems to me that 246TX is a workable alternative to 280TX.
I wonder what Bert is currently using? Hint, int. Nudge, nudge ;D But I’ll understand if you don’t want to share that.
Huntsman Composites (local dist) only carry 246TX in 20kg packs. But they’ll order 4kg packs of 246TX ($58.67 ea) and the H128 or H126 hardener in 1kg packs ($34.06 ea).
The ATL sales/tech guy in Qld tells me that his chemist is working on a new surfboard resin that is expected to be ready for production in 4-6 weeks. Its supposed to be very similar to the 246TX, but with UV blocker and pinhole resistance.
While it’s still in my mind - silly, you were spot on re local distro Well done! And thanks to everyone who’s chipped in bits of info and opinions. It’s been greatly appreciated!
Cheers all!
-doug
good one doug
glad to be able to help
i better go and check my post cure specs cause i didnt do it last time
thats sounds like a great price cause you get 4 boards from 5 kg
what temp is the post cure
cause eps has a low melting temp
ill hasssle colin about the surfboard resin i would like to try it
Hey Paul (silly)!
i better go and check my post cure specs cause i didnt do it last time
How’d you post cure? Temp and equip – if you don’t mind telling.
thats sounds like a great price cause you get 4 boards from 5 kg
I’m happy with it 
what temp is the post cure
cause eps has a low melting temp
Recommended post-cure is around 50C. Lower temp = slower cure is all - apparently. Yeah, I know EPS is low temp material. Gonna make sure I understand various temperature impacts on EPS before I subject a board to it. I said I am gonna make a new “oven” (old one’s too small) and I’ll test scrap bits of EPS in it. Can post what I discover on here, if there’s any interest.
ill hasssle colin about the surfboard resin i would like to try it
Yeah - I am wondering if I can get them to send me a small sample kit for free – got a pretty good converstaion going with the technical sales guy at ATL Qld so we’ll see.
Cheers!
-doug
i reckon they are real helpful with advice
and are a progressive company who are always improving
thats good service… they set me up an account straight away
and im on my second kit
i also get my glass from them as well and it worked out really cheap off a roll
cause it was 2 boards wide
im using an electric blanket and a thermometer for post cure
8 hrs at 40 degress C
check my post for the
“Help me im melting”
thread .so you know what not to do
as far as the price goes ive got some standard amounts worked out to mix by now
6 5 shortie
on an inside 2 oz lam i use 120 gram pre wet on a sheet of plastic
outside double 4 oz i mix 300 grams no worrys and just work slowly
dump resin in the middle the lenght of the board and slowly spread out to the rails
i dont push hard until its soaked in then i push harder to get out the air bubbles .
if you run out just mix a bit more
i mix in a deep container and then dump it or pour into a shallow tray to increase pot life .
but there heaps of guys that know more about glassing with epoxy then me…
defiinately seal the blank first
i use about 150 grams to seal tha blank and i go over small pin hole/joins in balsa witha micro ballons mix
i tape the outside of the balsa wood befor vacumming and have had no problems ever removing the tape.the first board i glued the sheets but this is time consuming
just keep our resin to a minimum on the inner glass and you wont get bleed through.
i think taping the inside is a bad idea and will lead to delams…
for the filler coat i do it as a cheater coat
and only use 150 to 200 grams per side
so total resin if you careful is about 1400 grams or less depending how much glass you use… tend to waste a bit
i think sabs uses a lot less cause his boards are 2kg and under
probably a single 4 oz would only need 250 grams i think
Hi Paul
Yep I try to match glass weight to resin,I have just finished two boards
Both 6’8" resin used on each board 420 grams
Finished weight the one with 3mm deck and 2mm bottom 1.84kgs the other 5mm deck 3mm bottom 2.1kgs
Thats still using 3oz inside as Icant find 2oz
Where are you getting 2 oz?
I do not seal the blank in fact I never put resin on to the blank and on the inner glass I allways pre wet the glass and let the vac pressure take care of it.
I trim all the balsa sheets with a jig and router then glue them with pva on a jig. It can be done in less than 15mins per side ,that way there is no reason to put resin on the blank.
I also seal the balsa on the outside some times using everdure and other times epoxy resin thined with acetone
The goal I think is to get to the point where you can pour small amounts of resin on with the outside glass and none of it is absorbed into the balsa ie a puddle should stay a puddle not slowly vanish.
Also pre heating the resin before mixing and pre heating the board helps it flow out a lot better.
Mike
man…youre the lightweight king…
are you sure your scale is accurate?
hey thanks for your recent tips…im getting way better g:r ratios now and im about to finish another one that should come in below 2.3kg…but this one’s got a better shape/rocker and hopefully better flex too…last board was a slight disappointment…a bit too loose and squirrely…still hopeful tho cuz i havent put it in its ideal conditions yet…
G’day Paul,
> i reckon they are real helpful with advice
> and are a progressive company who are always improving
> thats good service… they set me up an account straight away
> and im on my second kit
So far the Aussie company seems to be the same!
> i also get my glass from them as well and it worked out really cheap off a roll
> cause it was 2 boards wide
Might have to see how cometitive it is to mail/phone order from them. If they handle mail/phone orders.
> im using an electric blanket and a thermometer for post cure
> 8 hrs at 40 degress C
You’ll have to be real careful keeping an eye on the temperature! I am going to build an insulated box with a heating element (probably and electric blanket), thermostat and a thermometer (or three). That basic design has been really useful to me in all-wod handling (“kiln” drying).
> check my post for the
> “Help me im melting”
> thread .so you know what not to do
Yeah - I’ll re-read it to be on the safe side
> as far as the price goes ive got some standard amounts worked out to mix by now
> 6 5 shortie
My first is gonna be an 8’6"… Promised my wife The next one or two will be shorter and then longer again. I’ll need to adjust accordingly ;D
> on an inside 2 oz lam i use 120 gram pre wet on a sheet of plastic
> outside double 4 oz i mix 300 grams no worrys and just work slowly
Those amounts sound like in the same ballpark… Plus a bit for the 8’6", of course (I am thinking 150 & 400 respectively).
> dump resin in the middle the lenght of the board and slowly spread out to the rails
> i dont push hard until its soaked in then i push harder to get out the air bubbles .
> if you run out just mix a bit more
> i mix in a deep container and then dump it or pour into a shallow tray to increase pot life .
> but there heaps of guys that know more about glassing with epoxy then me…
Hhhmm… I was gonna pre-wet ala Bert. Thoughts? Anyone?
> defiinately seal the blank first
Abosolutely! This is something I have advocated on timber for years… And quickly came to the same conclusion for epoxy on EPS.
> i use about 150 grams to seal tha blank and i go over small pin hole/joins in balsa witha micro ballons mix
I am thinking around 200 grams on an 8’6".
> i tape the outside of the balsa wood befor vacumming and have had no problems ever removing the tape.the first board i glued the sheets but this is time consuming
> just keep our resin to a minimum on the inner glass and you wont get bleed through.
> i think taping the inside is a bad idea and will lead to delams…
Was kinda thinking of going with Bert’s “cheap tape on the inside”. Now I ain’t quite as sure. Any opinions on this too? In any case I think a bit of testing with scraps is going to be the go.
> for the filler coat i do it as a cheater coat
> and only use 150 to 200 grams per side
Yeah, I wasn’t sure how much I’d go with on this. From what you ahve said 200-250 will be the go for my #1.
> so total resin if you careful is about 1400 grams or less depending how much glass you use… tend to waste a bit
I was thinking that a 1.2kg with hardener (so about 1.6kg all up) wasn’t gonna be enough for an 8’6". I was thinking about 2kg all up - so the 4kg sound like the go. Still does.
> i think sabs uses a lot less cause his boards are 2kg and under
Lighter isn’t necessarily better for me right now - a log’s a log. Even if it’s for a 5’6" chick who weighs a bit under 60 kg (130 pounds for you yanks).
> probably a single 4 oz would only need 250 grams i think
Sounds like I may have overestimated then!
Thanks again,
-doug
Hey Mike!
Forgot all about the 1:1 glass:epoxy idea! Thanks for reminding me. You reckon that’s gonna go OK for a first-timer? I suppose testing is going to help me decide that, but… Also, wondering whether you pre-wet the same way as Bert does.
Thanks for sharing!
-doug
g day mike
i dont seal the eps just the balsa blank so the resin doesnt soak in
i was thinking everdure to seal, because i found thinned epoxy really slow to kick.
i get the 2 oz from ATL in auckland
id love to see a video of you glassing
because those amounts are amazing
yeah .i pre wet as well for the inner lam
but not the outer lam .I do the outer lam in the normal way i guess .
do you vac on the outer lam???
doug
i can see no reason to tape the inside
ive tested resin penetration on masking tape and it doesnt very well at all.
so thats a fair bit of area not actually glued…
and i see it as an unnecessary risk in durability…
even if your worried about bleed through (which doesnt happen if you pre wet the glass and squeegee excess) its no problem if you use plastic scotch tape
i have had good success with plasterers tape… like this stuff
http://www.swaylocks.com/forum/gforum.cgi?do=post_attachment;postatt_id=6257;
Paul, Dave,
Thanks - I think it’ll come down to testing with the particular materials and consumables I have on hand. At least, that’s what it sounds like.
-doug
hI Paul
Thanks fo that i will try ATL and see what they have.
i used ATL in Oz when I built my yacht They were a very helpfull company
The carbon rudders and stocks that I built on there advise sailed 55,000 nm with no problems.
I do the out side lam the same way only I weight the cloth first and match that weight with resin
Then rather than pour it all in the middle of the board I pour a very light line right down the length of the board holding the resin pot with one hand while following behind with the squeegy with the other hand
I do this five or six times each time pouring just enough resin for the squeegy to spread without excess going out the sides ,then let it absorb into the glass
There is very little extra squeegying to be done after that
I have tried vac ing the outer lam but found i used more resin that way
I sand the board then do a minimum fill coat usually about 90 gms with the glass and 40gms for the fill coat
I think the big pluss is to pre heat the resin first get it to the same density as water I also only work with small amount prefering to mix more as i go so as not to loose the thining heat qualitys
Mike
Ps a not of caution make sure that everdure can not get to the eps anywhere as it will melt it!!
I do the out side lam the same way only I weight the cloth first and match that weight with resin
Then rather than pour it all in the middle of the board I pour a very light line right down the length of the board holding the resin pot with one hand while following behind with the squeegy with the other hand
I do this five or six times each time pouring just enough resin for the squeegy to spread without excess going out the sides ,then let it absorb into the glass
There is very little extra squeegying to be done after that
sounds good ill try it .thanks mate
ill try and heat up resin first
however i dont sand before filler i just apply before lam is fully cured.
Do you ever have pinhole problems?
sand the board then do a minimum fill coat usually about 90 gms with the glass and 40gms for the fill coat
So are you saying that you do single 4 oz layer lam with 90 grams of resin
or was that the filler coat??
maybe i could do a double 4oz with 200 grams or less .(is that possible with your heating tip)
how durable are your boards cause im going for ultra strength.???
mate i reckon with those figure you could achieve 1.5 kg that would be amazing
dave cheers for the tape idea.
doug i think what you said about whats on hand sums it all up really
Hi Paul
Yep the amounts are right weigh the cloth then use the same weight in resin
Pre heating works well,I keep a heater aming at the resin bottles so that they are very warm prior to mixing ,I then mix only small amounts so that i dont lose the heat to soon and also so it does not exotherm in the mixing pot.
The only times that i have had pinhole problems is when i have rasied the temp after laminating to cure it faster
These days i try to keep a better ambient temp and I also pre heat every thing first then let it cure in constant or declining temps
Mike
I trim all the balsa sheets with a jig and router then glue them with pva on a jig. It can be done in less than 15 minutes per side.
do you mean youre making your balsaskins in less than 15 minutes?
for me it took 3 hours to glue up a sheet of balsa for a 9 footer, so thats 6 hours for both sides.
jimmyyoshioshibata.