I have an Aviso type , hollow board with kevlar in line for repair
Basically it got cracked on both the left and right top of the board.
What are the basics to repairing these space crafts?
Epoxy Im guessing not Poly
Sanding is going to be a pain
What are the internal guts, Do I need to split it open to look for damage, similar to a guitar with braces? I hope not.
And finally… why cant life be simple?
considering what you paid for it, I’d say contact Aviso directly and demand a refund.
You’ve got a challenge there. Carbon/Kevlar cloth is something to behold for difficulty to work with, it will cut but won’t grind. The crack and the soft spot could be bandaged by grinding down the surface with 36 grit power sanding then plopping a carbon patch over the surface, dont worry about sanding thru the cloth with power 36 grit!! the kevlar will stop the grinding right where it hits kevlar but it will thin down the laminate enouph to give you room for a patch, that should fix the crack but the soft spot might be a deeper problem that a surface patch won’t change, maybe the core is shattered? or maybe the backside laminate is broken also, a large semi bulky carbon surface patch might be an easy way to go, whatever you do, use carbon not carbon/kevlar, you’ll be forever trying to feather kevlar edges. The lump, grind it, cut it out, rebuild from backside laminate thru core and onto surface, too big a job. Maybe contact the builder to ask whats in the guts of the damaged areas so you can know what you’re coming up against. Please send pictures as you go, this will be an interesting repair. I like the go for the warranty idea also. A lot of repair patches all over the board might cause “hardspots” where it will want to break although that fabric is very strong.
That is almost certainly shear failure of the core. It is a common failure mode for cored structures with very strong skins, and those skins look STRONG. This is not good news for repairer! If it was a boat deck I would take a router with a tungtsen carbide cutter and cut through the skin over the creased area. Inspect core. If damaged router down to sound foam (that might be all the way through to the next skin), glue in another piece of core with epoxy thickened with colloidal silica. Sand it all fair and re-skin the area. Your problem is that kevlar, it just will not sand. I have had some success with a plane. Assaid above, Kevlar will CUT.
You will almost certainly end up with a patch over that area to bury the kevlar edges.
How did the accident happen? I creased my kevlar long board in big waves and repaired it fine. My problem appeared to be lack of compression strength in the deck. A carbon patch sorted that out no worries.
I’ve never repaired a board like this…here’s some coments…
Your title says “Aviso repair question”. Your post says that you have an “Aviso type board”. So Who made the board? Start with them. Maybe there’s a waranty or something. Maybe they can offer tech support and answer some questions. From my own experinces anytime you have Kevlar or Carbon fiber you also have Epoxy resin. Wear gloves ,the stuff will make your hands itch. The crack I would fix with regular cloth and epoxy resin. The soft spot is a concern…Not sure there. Wonder if there’s water inside the board? I am very interested to learn more about how to repair this type of board. Let us know how it goes.
Ray
id say it was a design fault
easy to damage
hard to repair
expensive materials
solution
low density core that will flex without failure
high density sandwich skin
high density perimeters
and just plain ole E glass
hard to damage
easy to repair
cheap materials
More info
the board is from here
http://www.hydroepic.com/index.php
Hydro epic, Where or how my friend got it, via a trade or doing some work for someone leads me to believe that there is no warrenty
Also there are numbers written in pen on one of the boards around the cracks so maybe they were test models. Or Hydro epic has already declared them dead and somehow the rose from the grave.
I am waiting to here back from Hydro epic, as I am not going to just ripping into the beast. The board does have internal framework, so that might make it a a real real pain in the a…
I will keep an update going…
A friend of mine who owns a shop had several of these boards returned. They were the early ones and had some design flaws. They were repaired and sold at a discount. Supposedly the design flaw was corrected. Something to do with more struts needed internally. Yours sounds like one of these early models. I was told they were hollow. So I would imagine the only areas that might have foam core would be nose and tail.
"Hydro epic, Where or how my friend got it, via a trade or doing some work for someone leads me to believe that there is no warrenty
Also there are numbers written in pen on one of the boards around the cracks so maybe they were test models. Or Hydro epic has already declared them dead and somehow the rose from the grave."
Hi jscottk -
Before anybody piles on Hydro Epic, it would be interesting to see if you can find out more about the situation. You use plurals in describing them… “them”, “they”… how many boards are there? Is the damage of the same nature on each?
“Numbers written in pen” sounds like they were returns or test models that were subjected to failure testing. Either way, as you say, maybe they had already been declared dead.
A “REAL” repair might involve splitting the seams and attacking any structural damage from the inside before gluing it back together. In any case, it sounds like a technical job probably out of the range of most of us.
I’d probably treat it like repairing a hole in a sheetrock wall. Cut out the whole damaged area with something small & spinning like a roto-zip. Shape ribs of EPS to fit halfway under the cut, and halfway exposed in the hole, so your new skin patch has something to sit on. Maybe throw a couple ribs or spines across the open area, inside. Fashion a new skin patch, maybe by saving the old one if you can, or using CF & 1/8" d-cell, corecell, balsa, etc. Glue it in with epoxy. Glass (plain old e cloth) over the whole patch, overlapping the old, intact area by a few inches. Hotcoat, sand smooth, go for a surf.
Don’t be afraid - sometimes invasive surgery is the only way to save the patient. Right now, its flatlining, you can’t make it any worse.
Thats how I feel about it as well.
Cut it open and start glueing, then fold the flap back over
Ugly is better then Dead
There are 2 of them both crack and crushed in different ways.
The deal is if I fix one I get to keep the other. (Sort of)
Ive dont a few repairs on race care parts made from carbon/kevlar hybrids and the industry standard is a “cut and shut” approach. The key to making this repair successfull is to cut out all areas that are stressed and/or fractured and laminate a patch that overlaps onto the undamaged cloth by 1/3rd of the cut away. This achieves a decent load transfer from the repair patch to the surrounding material.
Typically what I would do is:
Cut out the dammaged area as cleanly as possible and using a diamond wheel (a tile cutting blade on a hand held grinder is a cheap way out) use straight lines (not following the exact shape of the dammage). if you want to be really anal plan to follow the direction of the weave when making your cuts. Remove the damaged fabric. Take the shine off the surface of the area surrounding the repair with a grinder - dont worry about the frayed edges on the kevlar - unavaoidable and actually helps in bonding to the patch. now depending on the core you can fill this to make a good surface to laminate on to or insert some backing material to hold the patch in place (thin ply, card, anything… this isnt structural, jus to stop the repair patch from sagging into the hole.
then laminate your patch with whatever resin was used originally - probably epoxy (why would anyone make a carbon/kevlar board and use a resin thats not up to the task?.. then again… it wouldnt be the first I guess.)
Be carefull with the laminating - try to get a nice smooth finish and not too much resin. even use a peel ply to hel get a nice even surface (cosmetic reasons). once this has cured you have some work to do hoat caoting and blending the surfaces as the repaired surface will be raised from the overlap. take your time, hot coat then sand it out to get rid of the highs/lows, hot coat again and sand again… do this untill you have faired the surfaces to a blend.
hey presto… patched.
rif.
I did a double take when you said that this board was by “hydro-epic”. I instantly had to go over to the …“patent/hydro epOCH” thread to double check…wouldn’t that have been hilarious.
Hydro Epics with hand-written serial numbers were made in Oakland. They are some of the early ones. When the plant moved from Oakland to So Cal, we threw out tons (around 100) crappy boards. There was a bit of dumpster diving that took place shortly after, and some of these boards have been showing up.
You can call Hydro Epic and see if they’ll replace the boards or discount some new ones. There’s a one-year guarantee on them that’s past by now.
Fixing those kinds of problems is a pain in the ass. The mushy part is corroded aluminum honeycomb. You pretty much gotta get that out of there and replace it. Finding honeycomb will be tricky. Call HE and ask them to send you some scraps, or use PVC foam or balsa endgrain instead. You can patch using pure carbon instead of carbon/Kevlar if you want. Use epoxy resin and a vacuum bag.
I’ve broken more hydro Epics than anyone. When my boards got damaged like that, I chucked them. It’s easier to make a new board from scratch than to fix those problems. Seeing as they were problem boards to begin with… the end results will be marginal at best.
If you’re going to dive in… good luck. There’s some good advice in this thread.
I think it wold probably be sporting to change the title of this thread to “Hydro-Epic seconds repair question.”
No real reason to put Aviso in here.
I second the motion.
Hydro Epochs…done… title changed
Well the bad news is that my friend wanted the board back ASAP
Slop some epoxy on it make it water tight and give it back for waves tommorrow.
Thats fine by me as it was getting to be a time consuming task.
a few things I learned
The Kevlar aluminum honey comb material cuts easy with a sharp knife but hates to be bent, thus it would fall apart and crack when I tried to flap it open.
The material hat was bonded onto the struts or ribs made it hard to flap it open as well, a big sheet might flap but a small area just cracks. And not wanting to break it off the ribs anymore then I had too …
I did just what the customer wanted…Roughed up the area and chucked some glass and epoxy on it.
Here is a bit of a twist though…
The vent plugs were missing, so I was going to go to the hardware store and find new bolts that would fit the threads. (More time) Well I was changing a toliet seat yesterday and started looking at the plastic bolts, guess what fit perfectly?
hahaha…
If the board says “Hydro Epoch” instead of “Hydro Epic”, it’s really old - first generation stuff. We only made about two dozen of those boards total. That was the original name that Mark - company founder - came up with. When we did market testing, we discovered most people didn’t know what Epoch meant, or even how to pronounce it. I pushed for the change just to make getting the name out easier.
The technology of the boards didn’t change as quickly as the name did. The early Hydro Epics still had a fiberglass stringer that connected the deck and bottom together and the rails weren’t super reinforced as the newer ones are. The main failures of those boards were ones like you experienced, cracked rails at the joints, and stringers that poped off (usually on the bottom). Many boards snapped in half because of rail failure. When that happened the dumpster was the best cure.
Kendall, you sold me a Hydro Epoch 1st gen board for almost 500 bucks,… It came with a “rattling sound”. You told me it was fine and that the board was in perfect condition.
I thought that was pretty messed up that you sold me one of these messed up boards man,… I couldn’t get a hold of you at all after that sale. that board snapped perfectly in half in some small 3-4 waves in costa rica. First week on the trip too… I was pretty bummed about that man, I feel pretty ripped off considering you knew that these were already “junk” and you were still selling them and delivering them like that.
When did this sale take place?