EPS / Epoxy... Finbox install meltdown

General Discussion
21

stingray

eps has no real real strength

you can inlay new eps with a bit of 5min epoxy

glass is way overkill

what you do is route out a section and then inlay new eps and level it down and reglass it

inserts inserts inserts

do i hear insert

some in 20mm warvel sheets would be cosmetically superior then PVC

anyway ive never had problems with exotherm in eps because i use the correct epoxy resin for the job

no rags or water or any of that

one pour

no bubbles

not that it matters as inserts vastly superior then any other method when using eps

i actually modified a probox jig to route my inserts in

they work great and you use the same line up marks

intstalled in about 8 minutes

it sounds like all the problems people have that RR epoxy is not ideal for fin systems

you need a slow cure 4 to 1 that is runny and not bubbly like RR is

these are found at boatbuilders supplies

they are room temperature cured INFUSION resins

they have a pot life of up to 40 minutes

22

Paul ,

No bad to you in this regards,

But,

If he had done what I had instructed to start, he would even be in this situation…Sting could have done it in,140 degree heat,with a set-off time of a minute,and never had the fear of meltdown.

I know I’ve done it for kicks …just to see what would happen.

ALWAYS !!! Keep a bucket of wet rags,and a fan around…(this includes polyester/pu)

Why…

Because it works !

ps…Ray,If you would like…I have a s—load of slow set epoxy for laminating woods(skater-stuff).Let me know if you would like some…got plenty…it’s a 1 to 1 ratio…hard to make a mistake…crystal clear and set off times in normal temps are like 30min.-hour…at 100 degrees like 15-20 min.

Herb

23

Ray, for a couple tips of a very practical nature…

The trash can behind your local Best Buy will have all kinds of chunks of very good density EPS from when they unpacked all those flatscreen TVs. Crisp, white, tiny cells, good compression… and usually in little square blocks which are - gasp! - just the right size for finbox inserts.

White opaque pigment works just fine in 5-minute epoxy from ACE Hardware.

White opaque pigment also works just fine in Elmer’s Ultimate PU glue.

With hints like these, I’m sure you can figure out the rest. :wink:

24

Bringing back some great memories. :slight_smile:

I’ve been using ice packs on the deck of the board and slow RR hardener in 2# EPS. It’s a bit of over kill but pretty much guaranteed to not have a melt out. In 70F will take like 12 hrs to fully harden. Well worth the time for peace of mind though.

Rick.

25

I like the ‘‘keep it positive’’ part…

The unpredictability of results when doing after-glass installs in EPS with epoxy is the real problem No doubt

that it IS possible to avoid meltdown with some of these suggestions, but there’s also little doubt that sometimes

it will happen no matter what you do. EPS is a very good insulator, so sometimes all the ice bags in the world aren’t

going to help. I watched the FCS guys do hundreds of test installs and band-saw them in half for analysis. Large

sample testing is always more trustworthy.There was little rhyme or reason to the results. And a lot of installs that

looked fine revealed significant melting when sawn apart. The Fusion system (pre-glass install) was their answer.

If you want it absolutely safe, use HD inserts. (when we were doing those, the gray Divinycell was my fave).

Otherwise, take your time and do a two-pour, slow hardener, with cooling sytem of your choice (I like the peas),

or use another glue that doesn’t exotherm, or wait for a cold day, or just wave some dead chickens over it and

hope for the best…

edit to add: leave it to benny to come up with today’s recycle/re-use tip. Those dumpsters are full of useful stuff,

I’m surprised he hasn’t built a board out of glued-together packing EPS. Or maybe he has and I didn’t see it.

26

Rick,

Try the wet towels and fan(you can use ice water)…easier,stores better,and allows the resin to dry quicker.Plus you can switch out the wet towels as/if needed.

But…DON’T put the wet towels on liquid resin ! It has to be set first…not hard… but not liquid…it can be in a very fresh , in a rubbery state…just not liquid.

What does ice or water do?.. You may ask…answer: It doesnot allow the resin to get to critical mass temps abruptly,therefore no exotherm,smoking,cracking = meltdowns.

Herb

27

Can you guy’s recomend a name brand of this low temp slow set epoxy I can use for fcs. Hopefully something available here on the big island - ace or home depot’s all I got. Sure would be nice to pour and go - no babysitting. Mahalo’s

28

Both stores carry a slow set epoxy (30 min.).

Also someone else said they use epoxy putty , with good success.

I’ve even used quick set 5200 Marine Adhesive in eps/epoxy boards …does it work…one of the boards I did like 2 years ago is near dead…but the boxes are still holding just fine.

Herb

29

Generally speaking if you use the new FCS box you won’t have a problem. Fin boxes have never been a problem for us. FCS plugs have. This is one reason FCS decided to make a box.

In the case above a couple things.

  1. First the rout should be tight without a lot of slop. The slop requires more resin and builds more heat.

  2. Just as in all things epoxy get the resin out of the bucket first thing. Letting heat build inside the bucket is a major cause of meltdown.

  3. On very hot days keep the resin cool before you mix it. Resin that is 90 degrees when you mix it will exotherm much hotter than resin at 75 degrees.

  4. We do have a slow hardener which doesn’t create the heat that fast does. Having said that, I’ve installed thousands of boxes with fast and have never had a problem. But I’ve always followed the rules above.

30

If doing FCS, I’d advise switching to Fusion or doing HD inserts (no need for H-pattern if 4 lb or greater,

FCS has test data to back this up) for the ‘‘normal’’ plugs.

The low exotherm resins I’ve seen are specialized products not available at hardware stores.

If you HAVE to do the ‘‘normal’’ right into the EPS and want to use something easily available: I’d test first with hardware

store products, and they might need to be thinned as well; most of those are too viscous to penetrate the H-pattern (as is the putty).

Have you asked your FCS rep for advice?

31

Ditto what GL said…

The two most critical things are (1) tight hole, and (2) mix and pour… don’t fuss about it. If you’re used to poly, you’re used to moving, so keep that mindset.

Also, you can use fillers and pigment to minimize exotherm. I use white (epoxy) pigment and hollow glass microspheres (also saves weight and makes sanding easier). I always have some on hand because I like to seal with it.

No extra glass necessary, but you can do two pours.

Wet rags on under the install is good enough for me, and I only EVER use fast hardener.

32

If you’re doing the two pour method, how do do pour the resin in that tight space between the box and the foam?

33

squeeze bottle

the kind the ladies buy at the drug store to do home permanents or to dye their hair.

thats what the pros do

it’s too messy do it the other way unless you have good cups and steady hands

air bubbles are the big problem with the larger gap installs like PB

I used to use glue syringes until I found these soft plastic squeeze bottles the smaller the better.

If you travel alot

save those little squeeze out hotel shampoo and conditioner bottles and clean them out when their empty.

Then you don’t have to buy stuff from the store.

Another cheapo method is to scrounge offcut scraps

PU offcut foam inserts will also do the job if it is difficult getting the HD stuff also HD foam liek corecell/dcell is expensive.

PU foam usually has a higher temp rating than EPS which is why you don’t normally need inserts with it.

low exotherm 2 part epoxy jellies and putties also can be found at alot of online hobby craft stores.(CMP tip)

34

Howzit Herb, We use 5200 a lot for sealing cracks in foundation posts. How does the flexablity affect the adhesion since 5200 is flexable.Aloha,Wildog

35

I use ice water when I pour lure heards for marlin fishing.As the resin heats up and is gelled,

in the ice water it goes so it doesn’t exotherm as fast.Too many beautiful heads cracking before my eyes

made me do this in the temps we have here.

36

5200 might work ok with fcs plugs, but it is a no go with probox or other box systems. The last thing you want is the box or plug having flex in it. The box needs to be as rigid as possible. Let the fins do the flexing. I tried 5200 slow cure & 5200 fast cure with probox, all it does is crack the boxes and blow out on waves with more power.

I’ve had good luck with a bit of west system high density filler #404 (snow white color) mixed into the epoxy, also put a glass patch in the bottom and up the sides of the hole or box. Makes a nice bubble free install too.

37

No way 5200 would work for an FCS install. Or any other box, as you said.

We had a discussion about 5200 a while back. I love the stuff for 1001 marine and home and other uses,

but I would never install a box with it unless it was all I had in an emergency repair or something. Too flexible

and not designed to bond or seal foam. It would be asking for trouble.

I’m not trying to come up with ALL the conceivable adhesives for installs or repairs, just the methods and

materials you can trust.

38

1/4 Chunky peanut butter , 1/4 blue cheese dressing, and 1/2 Polyglycerine. Mix the three together and you’ll have a water tight strong install that you can munch.

39

Mike,

I 've used it with Red-X boxes Primarily,and only in eps/epoxy boards.It doesn’t hold up in poly boards,but eps/epoxy flexes quite a bit and allows for some box flex.

I have also done a few fcs boxes in 5200…results?

None of the boards have come back yet…and it’s been over a year since I’ve seen any of them.

I’m sure if the installs failed they would be on my door step by the next day.

My b@#ch with 5200…even the quick set , is the slow set-off times…very,very slow to cure time as well.

Herb

40

Great input so far. Thank you everyone!

Let’s go back to my first post…

I know what I did wrong and I know how to do a good install with ProBox. The main reason for the box failure was the fact that the Surfer’s Ass landed on the fin breaking out the box. The weak install by me did not help but the box would have failed anyway when the guy landed on it. This is the third fin box repair this year for the same guy. The other repairs are the glass over type of box…

Now, I’ve cut out this square of bad foam that I need to replace. Melted it down once and don’t want to melt it down again. Some say use polyurathane foam others suggest dumpster diving. I have both eps and poly foam. I’m going to think about it for a few days…

ProBox Larry called me today. He’s sending me a new replacement box for free. Thanks Larry!!!

…Looks like we will get some lessons/photos soon from ProBox on how they handle this type of repair…

As long as I have your attention…EPS foam takes on water much faster than poly. From a repair stand point what methods have you used to get rid of the water and dry out the foam.

THANK YOU !!!

Ray