Tragity strikes

well had the new charity board in the record setting sun on sat. for about 3 hours and the bottom swelled up about 2" in a 12" area, and the top deck felt soft and you were able to put pressure dings in it as you pressed it. anyone have a possible cause for this condition and or fix. the swelling did go down by last night but it delamed from the core.

Mark! I'm so sorry to hear of the delam! Your heart must have sunk.

Welcome to the world of low density EPS and epoxy. If you were using EPS of a density less than 2# it needs a vent, like this:

http://www.windance.com/default.asp?windance~shownewitem~CH_309

If you were using 2# plus, then it just needs a post cure. I throw mine in a hot box and post cure at 140 degrees for most of the day. The pentane or air inside heats up and expands causing the bubble and delam you described.

Are you going to try and repair it or start over?

i thought i used 2# eps , at least that is what i ordered , i dont know what to do , i just got it all done friday night at midnight, spent 30 bux extra shipping on some 451 fins to try out , and was not able to test it before i could send it off to the charity event.
i could fix it but i wont send it for the charity.

any ideas on fixing it

Try this:

http://www.boardlady.com/heatdamage.htm

Instead of the Vac Bag - just a normal lamination over the scarred section. Cut the delam with a fresh razor.

Jeff , will it bubble up again , or will i need to install a vent.??

If it's 1 pound you'll need a vent, no two ways around it. 2 pound is stiff, 1 pound feels floppy like the consitency of dried silicone seal almost.

Heat is the enemy of EPS and lamination. You had your borad painted black, too, right? My guess is that it was just the severe heat that causes the off-gas. I'd patch it and keep it in the shade as much as possible.

Also, it certainly wouldn't hurt to install a vent.

it has to be 2lb. because it was real hard to bend if i was to try to concave it. do these vents vent themselves or do you leave them open till you get it wet , and can install it anywhere on the top deck ?, yea the top was black with glitter in it. and the temp was 100 on sat.. You dont have to post cure 2lb. eps do you??

(Message edited by lakeside5_10 on June 09, 2008)

The vent's have a goretex membrane so they let air out but don't let water in.

If it was super hot and with that dark color, you most like got a weird concentration of heat. 130 is the killer point for most EPS.

Normally 2# plus doesn't need to be vented, but it's best to keep a hand laminated EPS blank out of the heat, especially if it's been painted a dark heat absorbing color like that. I had one that got the reflection off some window glass and it delamaned in a nasty way.

IMO, the best practice is to "pre" out-gas the blank. So before you laminate it, "toast" it That will get rid of a BUNCH of the trapped gas and will equalize at temps below that.

I always like to post cure epoxy, period. Epoxy will get soft after the original cure at temps above the ambient temp it cured at. So if you cured it at 75 degrees and then take it into 100 degree heat the epoxy will get soft and that may have contributed to the delam.

I would bet that if you are using 2 pound, you can skip the vent. If it were me, I would bake the blank after shaping and cutting the fin boxes - if you can get it up close to 100 degrees for a bit. Then after it's cooled seal it with spackle and laminate it. I typically wait a few days after the lamination is done and then bake it again. We get super hot here in the valley, so I try and bake it above 100 degrees.

it was 100f on saturday and i lamed the board at 80f, i am on the road to recovery , do you have a link on how you made your hot box . you say you bake it a 2nd time after lam , oris it after your last hot/glosscoat?

No, sorry Mark. I just whacked it out of 1/4" plywood and lined it with that foil backed insulation foam. My 'bro Dennis went to a building class down in Santa Cruz and he came back with some seriously innovative ideas, you might hit him up for plans.

The other thing that I started doing is to drill or cut a tiny hole in the fiberglass...back towards the tail where the kick pad will cover it up (two holes if there is a stringer down the middle one on either side of the stringer) and then I tilt the board slightly so that the hole is higher than the majority of the board and then throw it in the hot box. The hole allows any expanded air to get out, then I seal it up afterwards, with epoxy.

I do the postcure after my last coat of epoxy whether it's a lam coat or a gloss coat, all I want to achieve is the curing of ALL of the epoxy at a temperature higher than expected use.

Sway's has a great thread on your exact problem, tons of conflicting info so it's not an exact science. Might be worth your checking into, though. Might even be a slight consolation as you join with the masters who have done the same thing and how they approcahed fixing it in the future.

Part of the deal is the foam we are using. There is surfboard specfic EPS - I think it's the EDRO stuff and in the C grade pellets, I believe - don't quote me on those last two parts - and that eliminates most of these issues or at least minimizes the workarounds we have to do.

http://www.swaylocks.com/forum/gforum.cgi?post=378020;sb=post_latest_reply;so=ASC;forum_view=forum_view _collapsed;guest=18676923

Jeff,
cellofoam said they carry the c grade eps but they said it still has pentane , and would need to be aired out for 9 weeks. what heat element are you useing on the hotbox , i remember talking about the johnson control .

4 - 150 w incandescent bulbs and an old hair dryer with the heating element removed to blow the air around in the box (courtesy of Dennis) - right the Johnson control is how I regulate the heat - I wired the 4 bulbs to a plug that I plug into the Johnson control which I place inside the hot box. Then the Johnson control into the wall socket. Didn't you give me the link to the control?

I can take pictures this evening if you want - really it's just a plywood box with hinges for the lid and holes for the wiring and hair dryer. The only thing inside is the reflective insulating foam. I just made the dimension INSIDE big enough to allow my boards to fit and worked outward 2 inches in each direction. I don't even remember measuring it!!!!!

Not very scientific.

All EPS starts with pentane gas inside the pellets, well some blowing agent and I thought pentane was the most common. The issue with our low density foam is that it's mostly air. In between all the pellets is just air. When that gets hot it expands and is what causes the delam's not the pentane. You can test your foam pretty easily, if you take a chunk and tear it, properly formed EPS will tear those beads in half, the junk foam tears where the beads are formed - creating pukas.

My understanding - and this is PUSHING my limits, there is only one way that EPS is made and that is the steam fusion. There are two ways that EPS products are made Block and Custom molding. The Custom molded doesn't out gas at all, the Block molded, because the beads closest to the edge fuse and block the steam, leaves the gaps where air get's trapped inside and causes these issues.

When we use the cheaper non-custom molded, I always bake, seal and vent less than 2 pound and bake, seal and vent (holes) during post cure the 2#

I have heard of seasoning the EPS, but I am not familiar with the process or the reasoning. Also, not familar with cellofoam. Sorry 'bro.

thanks on the hotbox info , will have to get my johnson control back from the fermenting fridge. i may be able to get foam laser wired to my specs.www.cellofoam.com/home.htm - 18k

Just a quick retro fit of a Casica vent.

The small piece is the gortex vent, the larger piece the sleeve the gortex vent threads into. Hex head is a 5/8" standard depth socket will work.

I traced the bottom of the sleeve on the board in preparation for routing the hole.

A quick pass with the router and the hole is ready. I merely epoxied the sleeve into the hole and weighed it down until it cures.

nice weight, and i luv the wood effect

Do you like that weight? I have an entire shop of tools JUST like that

I was following up on that Sway's thread and Pete C, who I believe is fairly knowledgeable, was claiming that EPS foam was mostly CO2. I had never heard this before and in fact most EPS manufacturers routinely state that EPS is mostly air - typically upwards of 90% air.

Texas Foam states:

"EPS is comprised of 90% air."

http://www.fusionpage.com/synapse/homepage/view.cfm?edit_id=39&website=texasfoam.com


Univfoam states:

"Because EPS (expanded polystyrene) is mostly air, it makes an excellent insulator. The thousands of air pockets create an effective and economical thermal barrier."

http://univfoam.com/products/styrofoam

Most other authorities state the same thing. Segway composites:

"EPS foam by its nature is mostly air, and depending on the density of the foam, there will be more or less air between the fused closed cell beads of EPS."

http://www.segwaycomposites.com/EPS-Foam.html

I'd place my bet on the majority and that the low density block foam we use is mostly air and not CO2. This would seem to me, to indicate that a simple vent that will allow the equalization of pressure caused by heat inside the board to be an effective solution to delamination with low density EPS foam as a core material.

and all my boards will have a vent , going to pick up some 5' eps this friday to build a new 4.0 and start a 4.8 phish template from my xbc and a 5.0 hwailer longboard ( fat & slow ).
enjoy your new motor ,
mark

(Message edited by lakeside5_10 on June 14, 2008)

I'm going to have the same problem. I ordered vents but I don't think they will be here in time for the TWC.

THIS hot weather blows , sorry about your problems Show , we will get them next time, the next board will be bad ass.

Hopefully I'll have something by Wednesday evening.

Next time I buy resin it won't Resin Research and Add-F. This stuff never goes on with out making bumps and fish eyes. Its like built in traction. It's impossible to get a good finish. I end up sanding, then over sanding and running pin pines and the like.

Last time I used it I filtered twice. It still needed sanding. So I put on another layer tonight. This time I filtered with a vacuum cleaner bag. Still came out lumpy and bumpy.

Man I'd love to spend a day watching a pro glass boards.

so what other epoxy is their to use without any problems , can u use poly on eps or not??

The issue is not peculiar to RR and it's just on the gloss coat. There are a ton of epoxy wholesalers, in fact if I am not mistaken there are only like 3 or 4 manufacturers of epoxy and all of the wholesalers buy from those manufacturers and relabel, so it's not like switching brands changes much.

Most of the high gloss boards you see that use epoxy have a polyester or polyurethane top coat. It's funny, you read that those boards are made from epoxy, but they have more PolyU than Epoxy by weight or volume.

You can't use polye or polyu on EPS, BUT you can use both on TOP of a final epoxy lamination, or cheater coat.

so we can top coat with silmar 249 with no problems , Mark at us composites said that it would not stick to epoxy and should not do it . is this true or not??

No, it'll stick. This article might prove useful to you:

http://www.westsystem.com/ewmag/22/polyester.html

Polyester achieves it's highest strength when the bond is chemical, not mechanical. Polyester and Epoxy have different curing chemistry's so a chemical bond won't happen.

Polyester is weak in comparison to Epoxy, but it will certainly stick to Epoxy, at least in the short run. Maybe Mark meant to say that it would just be the weakest part of the structure? That's certainly could be true, but it's not like it will peel or fall off when applied. No doubt over time Polye will separate from epoxy.

A 2 Pac is no doubt the best answer.

uhhhhh, 2 Pac?? sorry . he is dead hahahah

LOLOL - polyurethane like for auto finishes.

starthane, i used it when i painted, well will the 249 i just ordered work fine ??

It'll stick to the epoxy, yes. It'll fail eventually too. I'd guess it's dependent upon usage of the board. If it sits mostly, no problem. Bang it around, it'll chip. Polyester isn't an adhesive like epoxy and without imbedding 'glass I'm sure it's prone to failure at some point.

So today at work I had to do a little research on surfactants. I couldn’t’ help but think about my hobby problems. There’s something called cloud point. When the temperature is too high or rather when the temperature reaches the cloud point long “worm like” chains form. That might be what’s happening. You have to get Add-F warm enough so that the wax melts. But if you get it too warm you probably reach the cloud point and form polymer chains. I’ve been microwaving the resin to make it less viscous. So maybe I’m reaching the cloud point. It can be as low as 60C for some surfactants.

I think I want a surfactant with out the wax for the finish coat.

Ed, how cold is it there when you glossed last? My Additive F doesn't separate, it's a solution as I type this - we also get close to 100F degree highs during the day and maybe a low in the 70'sF.

During the winter the can turned in to a rock.

Lately we've been in the 60s to 80s. It was fairly warm, 80ish when I applied the zit coat. We're a lot more humid than you are.

There's a fair amount of left over junk in the filter.

I know that RR is uber sensitive to temperature and the direction of the temperature change. You have to filter it a ton.

how can someone sell a product if the gloss coat might seperate in use , i think i will not use the 249/