? for all the RR users

General Discussion
1

I’m a total convert to RR epoxy, I just can’t see any reason to use anything else anymore… Well, unless I’m going to do a huge resin volume for an acid splash, but anyway.

I’ve been very impressed with the impact resistance of RR epoxy, but I’m wondering if there is anything I can do to prevent “bruising”. When I thump one of my epoxy sticks, in a scenario where a poly board would ding, the epoxy doesn’t ding, but it leaves a spot where you can see the weave in the lam. While this doesn’t seem to hurt it structurally, it is kind of ugly, especially on a wood lam board.

So, is there anything a person can do at some point in the lamming process to keep that from happening? Or is that just the norm? here is a shot of what I’m talking about:

2

Hey Shwuz,

Regardless of what’s under it a ding is a ding is a ding is a ding in a fiberglass/resin lamination. A concussion will shatter the glass/resin bond and the only way to fix it is to very carefully grind away to broken section so that I can be relaminated and feathered in to the surrounding surface. Good resins may the proceedure very straightforward and little if any strenght is lost.

Mahalo, Rich

3

Sorry this is in no way an answer to your question, but that board looks lovely, any chance of a full shot? What wood is it?

Cheers

Jase (MMM)

4

HeyFatbaslardass,

If you’re referring to my suggestion to Shwuz. I’m simple cutting to the chase. I’ve seen photos of this and other boards from Shwuz’s hands his work is very high level stuff. You gotta do what you gotta do to fix the problem. No sense cryin’ about it or being judgemental. By the way, got any answers for him?

I’ve been doing repair work all my life and one has to just get on with it and hope the result will be acceptable. My comments are in no way intended to a reflection on his work which hs clearly superior to anything I could dream of doing.

No Worries, Rich

5

No reference to anything, just fancied a look at the whole thing. No need to defend your corner, it aint under attack!

Jase (MMM)

6

i think when he said “sorry this is in no way an answer to your question”, he was referring to his own comment where he asked to see a full pic of the board…not your initial reply. hakuna matata.

7

Hey halcyon,

I absolutely understand what you’re saying about dings, but this phenomenom I’m trying to find out about is occuring even on pressure dents, not just spots where the glass would ordinarily have cracked. That’s why I was calling them “bruises”, becuase every impact or pressure is making the weave show that way.

So, is there a way to keep that from happening every time the lam is flexed a little bit?

8

just a thought…S-glass supposedly has greater memory than E-glass…perhaps it might be worth the extra $$$ for S-glass if it’ll bounce back to it’s place rather than fracturing at the slightest bit of pressure.

9

Duh!! egg on my face-- guess I was projecting. Soulstice, right on with the post reference and the call on S glass.

Bottom line is if you don’t want the lamination to flex you just have to put more glass in it. I’m using double 4oz E glass on the bottom and 6oz S glass deck with a 3/4 patch on all my of (Clark Foam) boards and the comination does dent occasionally but isn’t showing any fracture damage at all I paint fairly generous hot coat on the lamination when its done and go to work with fairing the surface. That’s about it.

You might consider sanding the board and putting another glass on the deck and feathering it into the bottom. The board will gain a little weight but it might be worth it. IMho it’s too fine a piece of work not to protect well.

Mahalo, Rich

10

Well, this isn’t really a structural issue, more of a cosmetic one. On the first board I made with RR, I had 24 oz on the rails by the time all the lams were on, and it still showed the weave upon pressure. Maybe these photos will help explain better. I’m thinking that when the glass flexes within the epoxy matrix, the individual fibers “slide” just a little bit, reasserting their individuality and once again shining in the sun. Is there a way to keep this from happening? And am I really the only one who has seen this?

In these photos they look like dry spots in the lam, but trust me, they aren’t.

11

uh oh.

Lemme ask you this–are they only occurring in the laps, or in areas that were lammed in more than one layer / kick?

could they be places where one layer of weave is separating from the next?

My thought is that they might be from something on the surface of the previously hardened layer that kept the top layer from bonding as well. light impact=separation.

I had a place like that on my first RR board, on the rail, right where I would put my hand if moving the board around during glassing. I must’ve moved it without gloves on. now I use gloves, and clean ones, to move the board, from the moment I finish shaping to the final gloss. it doesn’t help my backyard/apartment setup isn’t ideal, but a little extra effort keeps the project (and my pad) clean.

wells

12

Hey Schwuz,

I could be wrong but the weave that’s showing on the foam board is all on convex surface high spots of the board. These are prime locations for eposing weave during the sanding process and where it will show if there is excess glass or irregularities in the lap laminations. I don’t think the photos show dings or dry spots. I have found that taking a auto body fairly rasp while the epoxy is still rubbery and fairing things out with a very light touch then hot coating helps decrease the amount of weave that shows during the final sanding process. A perfect lap job is the ticket as it is very easy to expose the weave on steeply convexed surfaces. You gotta be super careful sanding there. I know some pros that make it look easy. I’m not one of them.

Mahalo, Rich

13

They happen in the flats as well, but not as much.

My sanding technique is far from perfect, admittedly, but the areas I highlighted on the white board were water-clear before known instances of rough use and heavy knee- and shin-contact.

It just seems like in areas where poly would either permanently deflect or crack, this epoxy is bouncing back, which is a good thing. It is also staying watertight, another good thing. But it is showing the weave where it has been flexed, not such a good thing.

I do appreciate the help in trying to troubleshoot areas of possible technique shortcomings as problem areas, but I am certain that this is taking place just as I have described. The lam is clear, it gets impacted (blunt or hard) and just like that you can see the lam.

I guess what I’m looking for is something like, “Oh, I’ve ran into this, you’re using too much additive F in the lam, impairing the glass/resin bond” or “are you using glass brand X? It has an unusual coating that lets the fibers slip upon bending.”

Maybe if I show more photos…

These photos show clearly there are some small flecks of dry fiber dispersed over the lam, but the areas of impact look totally dry, and you can see where they pulled loose small dots of weave just on either side of the impact zones. both of these were hard edge impacts, and even though they look rough, they can barely be felt when handling the rails with eyes closed. They bounced back great, but discolored more than I would have expected. These are just more serious examples of the same thing on the “knee thump” areas I showed on the white board.

I can see why this would happen on penetrating type impacts like the ones shown above, but why also on the blunt bumps?

14

If I remember correctly you wrapped your rails with veneer. Do you think that the EPS rails might not give enough support under impact allowing the veneer to momentarly depress into the foam. When it springs back the resin-wood bond might be weakened. Just a guess…

15

Shwuz, I’m with where DanB is going - I think its showing the downside to using a very thin sandwich core material like veneer (or like no core material at all like on the white board). I’ve got those spots on my epoxy over EPS boards, but none on the ones with a 1/8" or 1/4" sandwich core material. Remember that the thicker the core, the stronger the sandwich - to the point where the core is so thick it might as well not be a sandwich, anyway.

Bob Miller recommended to me that if I’m going to use plain wood veneer (1/16, 1/32, 1/64 etc) I also use 1/8" d-cell. Your sandwich is then glass/d-cell/veneer/glass…no dings or pressure dents whatsoever except under the most severe circumstances…

16

If you doing veneer like that board in the picture you could use 2020 resin and it will be much better at surviving impact than 2000. Should be just right for what your doing.

17

I’m actually pretty pleased with the impact resistance on the veneer boards so far. Like I said, they look ugly where they got smacked, but you can barely feel any change in the surface, and they stay watertight. I really only posted those photos to better illustrate what was happening on the clear lams.

My main objective here on this thread is to find out what causes this on clear lams:

Where a blunt impact causes the glass fibers in a previously clear lam to become visible. This one phenomenom in particular is what I’m trying to chase down here.

I really appreciate the effort everyone makes to help me here, but I really feel like nobody has really gotten what I’m trying to ask.

This area where you can see the weave here was perfectly clear before a particularly ugly knee thump. lapping the rail, there is about 24 oz of glass. On the flats, 14 oz. It is not a result of sand through or uneven lamming or uneven hotcoat or final spray. It is the result of the glass fibers shifting within the matrix of the epoxy when the lam gets over flexed on impact. By flexing them slightly out of place, they loose the transparency that they gained by being wet-out with a liquid resin.

I don’t have a problem with the physical durability of any of the lams I have made using RR. On the contrary, it is the most amazing thing I have ever used. The question I have regards the aesthetics of the glass after it survives an impact.

My question:

Is there some part of my process that I could modify to give the glass/epoxy lam different characteristics, specifically so it could survive the same type of abuse it is already surviving, but without losing clarity by way of the weave becoming visible?

Maybe if I used S-glass?

Tell me someone understands what I’m trying to ask here! I love the durability of RR epoxy, I just don’t want every would-have-been-ding to show up as visible weave, even if it is perfectly smooth and water-tight!

18

I think that Epoxy is just more flexible and impact resistant and is made to laminate under pressure better than try to fit the old room temp glassing techniques and schedules. I remember getting the same looking pressure dents on some of the first shortboards with heavier glass schedules and I did dark wood single fins that would show those same impact marks. Which leads me to think that the destructible thruster is white for a reason.

My son and I had a board glassed with R&R epoxy last summer by the same guys (HDX) that did Rich Harbour’s Epoxy longboard experiment. It’s just too good to put on crushable Polyu foam. In the photo you can see that on the deck where there are only a couple layers, the foam gives way and the resin can carry the load over a wider surface and not fracture the fiberglass, but it leaves a crater. On the rails where there are five layers of fiberglas the impact doesn’t go past the shell layer so the force is taken by the glass cloth and shatters within the flexible resin. In polyester you would have fractured and shattered resin, but in epoxy the surface of the resin maintains its integrity and transfers the impact.

You would get this impact glass shattering with any MULTIPLE layer glass schedule over lightweight core or thin veneer/lightweight core in my opinion. RAILS.

Also some wood is very thirsty and can soak the resin right out of the glass.

Thicker sandwich core to transfer the impact!

OR light colored balsa wood with light weight vacuumed cloth.

OR? More tests are in order. I kinda remember Bert saying there were other cloths involved? Could he be finishing the outside with polyester? Ouch.

Those impacted fibers are just state of the art for now, at least until “you know who” leaks some more info. I feel your pain…

19

There!

You feel my pain, indeed! So, I’m not doing something wrong, it is just the way it is with RR.

Ok, I can deal with that. Fair trade, aesthetics for impact resistance, I guess.

Now, I wonder…

Do you suppose if a person were to do color (airbrush, paint pens, etc…) over the hotcoat and under a glosscoat, it would help to hide those fibers?

20

Shwuz,

There has got to be a fabric out there that is more flexible than fiberglass cloth that will bend with the epoxy resin and “snap” back into shape.

I feel that Bert is going thicker with the wood and thinner with the fabric for a certain reason, maybe he faced this already like we did in garages around the country in the 70’s. Part of having certain materials is purely cosmetic. If you go a certain way on any extreme you give up another part of the total package.

Maybe to have a beautiful wood board like a Surftech you have to give up some strength to balance the cosmetic issue. Could you sell one of those wood boards if it was all shattered looking after a summers use? But if you are only replacing one or two here or there cause they snap, big deal…

Just use light cloth and fewer layers on the surface, with a higher density foam sheet, like that Last-a-Foam 8 pound density by 1/8 of an inch thick underneath the higher impact areas. Or balsa.

An artist can cover anything up, but at what point do you say that’s not the solution? Pain plus more pain equals gain?

I wish cmphawaii would throw down some thoughts, cause I definitely want to build a board like you guys, freakin beautiful!!!