Big repair on Pau Hana SUP. Waterlogged/Delam

[julien]

Went looking for a SUP to fly fish from with my dog and picked up this beater for $150. Pau Hana Big EZ Angler. Most of the deck all the way to the rails is delaminated from the EPS foam inside, presumably from the stupidly designed stake out holes that let water in. I am trying to figure out the best way to rebuild the deck so it will last me many years of fishing adventures. From my research tonight, I gather that these are the steps:

1. probably cut the whole skin off the deck with a dremel and let the EPS dry in the sun (or out of the sun under a black tarp?) for a while.

2. Once acceptably dry, build up the foam deck and fill any voids (we’ll see how good the EPS looks after removing the shell) with some 2 part expanding foam. Any recommendations on a particular product in the USA?

3. cut/sand to shape and fill any holes with microbubbles, as i’ve learned it’s called.

4. sand to final foam shape

5. fiberglass cloth/resin overlapping the still intact rails.

6. hot coat over the glass.

7. sand until smooth and then apply some kind of finishing coat?

I am just wanting something usable and dont care how it looks at all.

I still have many more nuanced questions for each step, but I want to make sure i am getting the basic outline right and that the final product should last me and make the project worthwhile. I’ll upload some pics tomorrow detailing all the damage.

Thanks!

[jrandy]

Welcome to the forum.
-Uploading pictures would be good.
-You have listed the basic steps.
-EPS can melt at ‘under a black tarp in the sun’ temperatures and similar exposure to higher temps may have helped to initiate the delams you are seeing.
-Does the board have vents?
-2-part foam and lots of epoxy with ‘micro-bubbles’ (? micro-balloons) (hollow glass spheres) will add weight.
-The pour foam might not be needed, this will not be known until one digs a little deeper. Sometimes the glassing can be removed with minimal foam loss/damage.
-One of my current boards is a stripped and redone EPS/epoxy board I built earlier.
-For a heavily repaired utility board I wold consider a painted finish after sanded hot(fill) coat. UV is not a friend to epoxy.

[OSS1]

Cut the glass out and glue down a piece of divinicell, cork or EPS foam. Then fill, glass etc. Use six oz.

[julien]

Apparently I can only upload 1 photo since im a new user. and imgbb isnt allowed here. what am i supposed to do?

[julien]

[lemat]

From my experience of this kind of repair when layer delam pull out, only need some resin and micro. What i do is squegge a coat of resin micro on blank lay fiberglass on this let it soak and squegge an other coat of resin micro over. When cure sand this flush and lam over.

[OSS1]

A lot of the time you can cut out the glass in a patch along the rail lap and peel it back cleanly. If done carefully very little foam will come off with the glass. You can then use Epoxy resin and a slurry of Cabosil to reglue the patch to the deck. In your case the veneer may peel off with the glass. Do some filler wherever necessary and cover with cloth and Epoxy resin… If the reglued deck is below the surface you can lay on cloth and Epoxy to get it up to the level it should be at the rail. My recommendation for divinicell or cork glued down to the deck is based the possibility that the foam may have collapsed more than 1/8”. Layers of cloth and filler would add too much weight at 1/8 or 1/4”.

[julien]

The bottom has some delamination too, but at least it’s not cracking at the surface or anything. I’m hoping I can just ignore that part. I think I will be able to remove the deck, or at least most of it, without tearing much foam underneath as it is already so badly separated, I should just be able to pop it right off after making a big perimeter cut.

Yes, Micro-balloons is what I meant to say. If foam filler of some sort is deemed necessary, whether an EPS sheet or some 2 part expanding foam, I don’t mind if it adds some weight (say up to 10lbs?). This won’t be a high-performance surfboard, I just need it stable enough to stand on. All of the EPS at my local hardware stores has a reflective face on it. Does that matter?

Why was it asked if it has vents? I don’t see any venting other than the little screw-in gore-tex vent plug on the very rear top.

Are these things supposed to be perfectly flat on the standing deck? Or slightly convex or concave? This one is all over the place, wavy from delamination, and I’ve never seen a paddleboard before so I have no frame of reference. From images online it looks pretty flat.

I’ll do some kind of paint finish.

Any particular product recommendations on:
paint
EPS (and an adhesive to glue it down)
hot coat
6oz fiberglass cloth
???

Guess I’ll put together a little shopping list and budget it out.

Edit: long post here, and people are replying as I type this out…

lemat,
that sounds so simple, I really hope the job is that simple. So you are doing this resin-micro/glass/resin-micro sandwhich all at once before anything dries/cures?

OSS1,
I think you’re right, it’ll peel off cleanly. There are some spots that are solid where I don’t think it would peel off nicely, but I can just finish the cut before those spots - or just do the whole thing in one clean cut since the majority of it is screwed anyways. The problem is that there is delamination between all layers in some spots. What I mean is the foam is delaminated from the deck, and the deck itself has delaminations between the wooden veneer and the top glass/epoxy (or whatever they use) coat. All that to say I’m not even sure I want to reuse the top piece - we will see when I get it off I guess. I’m trying to do this cheaply as possible - is EPS cheaper than cork or divinycell? My gut says the foam has in fact collapsed more than 1/8" hence the deck being concave rather than flat.

[stoneburner]

Cork sheet over and under FG would make a tough deck skin. Lighter than epoxy resin.
This is what I experiment with.

Cork Rolls

[julien]

After looking again, it seems the skin might be re-usable. There will be some spots where the timber veneer is just too nasty to reuse, but I can just glass over those small spots. Here is a pic showing how bad the warping is.

Also, I weighed it and it’s 10lbs over spec, which means over a gallon of water is sitting in there.

[OSS1]

Once you get the deck off; I would lay it somewhere safe and dry and let it drain for a few days. Deck down. You’ll probably have a good sized puddle.

[julien]

Definitely… especially since I just took it on the water to test it out and waterlogged it even more.

The foam is very clearly degraded on the majority of the board. Is it salvageable? I can easily scrape it away in all the whispy looking spots, like overly popcorn-textured walls. How will I proceed once dry? The foam becomes a little bit more structurally sound if I scrape about an inch or so of the top foam away, albeit waterlogged. I do wonder if it will feel sturdier once dry.

The much denser foam they used for the accessory mount anchors fared well and the glass was still well-adhered to it. Some of it popped out of the surrounding foam and stayed adhered to the deck layer.

[OSS1]

Others are probably right; Two Part Pour Foam. Then shape it down and glass… Otherwise Divinicell vacuumed onto/into the deck. Surformed and filled as necessary.

[julien]

Do you have any videos or pics showing Divinycell being blown in as you described? I thought Divinycell was just a sheet of foam. Any good reason to choose that over a 2-part expanding foam?

[jspr]

Divinycell is PVC sheet foam , … maybe you find some good info on the board lady (The Board Lady - Repair Menu) homepage.

[lemat]

Delam top, delam bottom, sponge eps very degraded, it smell hard trash can.

At this stage, better, easier, cheaper to do a new one.

[doc]

I’m with lemat; by the time you add up the expense of foam(s), fillers, resin, cloth and what have you, it gets pricy. Plus the value of your time involved, if you’re worth more than three cents an hour. There is really nothing left of the original that’s worth keeping.

And what you’re gonna wind up with will be heavy and awkward, structurally questionable and really, really ugly. The Mythbusters did a segment and yes, you can get s#it to take a polish, but do you really want to?

In truth if you bought a Great Big Urethane Foam Paddleboard Blank, lightly hand sanded the lines the mold left and simply glassed it with 10 ounce cloth (see a myriad of posts here) and polyester resin you’d have something a lot better. Or look for another used paddleboard, and now you have a Really Good Idea of what to watch out for.

hope that’s of use

doc…

[julien]

That’s highly discouraging to hear, but I already have it and have put in a little work, so I might as well price it out and try to finish. I went in expecting to pay $550 for a functional board, and got it for $150 when I found it was damaged. I accept it’s a labor of love at this point. These ultra wide boards are kind of hard to find around here, which is kind of why I just snagged it up in the 1st place, even knowing it needed work.

I think worst case it’ll add 10lbs (~5cuft of 2lb density foam).

I need some guidance in planning how to reglue the skin on the foam when it’s all sanded to shape. The skin peeled off in one big chunk, so it’s just a matter of sanding the old crap foam off of it and reglueing it down. Referring to an earlier reply by OSS1, not sure why I would need cabosil for this part as it’ll be a horizontal flat surface when I glue the top piece back down? There are some parts where the epoxy resin delaminated from the veneer - can I slap something in between here to reglue, or should I completely separate and re-epoxy-resin the veneer? Just not sure how to go about it.

Here’s my little price list. Let me know if I am missing anything.

[doc]

Hi Julien,

First, like your spreadsheet. I’m a fan of spreadsheets. While I don’t see quantities, I’m okay with it in general.

Though you haven’t figured in labor. Me, I always do. And even at minimum wage, well, that’s gonna mess with you.

Ahmmm, I know how you feel. I’ve had a few projects like that. They become time and money black holes, they really do. To begin with-

You are going to have to get out all, and I do mean all of the original foam. It was weak to begin with and after soaking and drying it’s rotted, for all intents and purposes, has all the strength of cotton candy. Nothings gonna stick to it.

2-part pour-in foam. Well, yeah, but- bear in mind that the 2 lb stuff is really just meant for buoyancy in end compartments in small boats. Structural strength and compression resistance ain’t there. You can either put some fairly dense divinycell PVC foam sheet inlaid on top of it ( a tricky bit of routing and inlaying) and thick glass or use way heavier foam AND REALLY thick glass. Or else it will start delaminating immediately, foam crushes and …yeah.

the weight is starting to go up. So is the cost.

By the way, your deck deformed as it delaminated. Odd bulges and so on. So yeah, you’ll need to use some sort of filler (cabosil plus resin) in there. Glue/resin alone won’t be enough. Yes, more weight, plus it makes for weird hard places in the deck, which lead to delamination.

You might want to just put a veneer over your new glass, then another layer of glass over it, the delaminating deck that was there is already falling apart, do you really want to go through a lot more work to stick it back on just to have it come apart again?

By the way, the best way to do a lot of this is vacuum bagging. Bags, pump, peel ply, etc etc.

Lots of sanding and grinding. Discs, paper, etc etc. Lots of time.

You see where this is going?

Look, I understand. You get into something and you hate to give up on it. And there are some boards with a lot of intrinsic or emotional value, say somebody’s father’s board or something rare and historical, that I have fixed when they really weren’t worth that kind of effort. But… there is something called the sunk cost fallacy.

This is a factory-made thing that was popped out of a mold somewhere on the Pacific Rim, quite probably built by low paid help who never saw an ocean. They made a gazillion of them, maybe changing colors and brands. Be patient, another one will come along in good shape.

hope that’s of use.

doc…

[julien]

I’ve also done some of these black hole projects and I don’t seem to learn any lessons. I am trying to talk you out of talking me out of it.

I was not thinking that I’d have to remove all of the EPS. It’s pretty solid once you scrape an inch or so away. Not as solid as new, but I can stand on it just fine. Even if the pour foam didn’t stick to it as you say, it would still be there occupying a volume, so what would it matter if it sticks or not? It looks like #2 urethane foam has ~40psi compression strength. (https://www.aeromarineproducts.com/wp-content/uploads/2016/03/2lb-foam-tds.pdf)

That’s plenty to withstand my tiny ass (10psi maybe?) on a paddleboard. I haven’t used #2 foam in probably 20 years, so I actually have no clue. But I would imagine with veneer/glass on top it #2 foam would handle me. I mean even the rotten EPS crap handled me standing on the board when I tested it the other day, and a new pour foam can only be better than that.

Say I do proceed with pour foam and get it all sanded to shape…there will be little voids after sanding, right? That’s what q-cell is for? (it’s missing from my spreadsheet)