Quote:…compensate for this by use of different fabric to some degree. So many possiblities with use of different fabrics and how you use them.
…
I realised you were asking Sabs, but thought i’d post seeing as i had overcome this one a different way.
for some unexplainable reason i seem to get the best ride with a flexier hull than deck (this was an accident, my dual density blank plus heavier deck glass was designed to simply withstand denting better). however when i produced a stiffer structure with perimeter stringers the ride deteriorated (I use highly domed decks). So i’m now thinking of deliberately increasing hull side flex by incorporating some of the Resin Research flexy formula into certain key areas. I know you are in the boat industry, can you suggest some fabrics that you would think suitable for matching with a flexy resin?
i suppose requirements would include either doesn’t absorb much resin for the lam on the inner side of the skin, or if it is suitable for an outer lam (ie would need to be tough to withstand dings) then resin absorbtion wouldn’t be such an issue coz the bleeder would soak it up.
Hello All,
I came across some glass info in a composites for aircraft book and thought posting here would be just as good as anywhere. Maybe common knowledge but it wasn’t to me.
“S-glass is roughly 30% stronger and 15% stiffer than E-glass at about triple the cost…S-2 glass is a variant of S-glass made by Owens Corning which has somewhat better properties. A very interesting form of S-2 glass is HOLLEX which is composed of hollow fibers. The resulting fibers have the properties of E-glass but with 30% less weight.”
" KS-400 is a blend of Kevlar 49 and Ownes-Corning S-2 glass which is intened for hand lay ups. The glass component facilitates wet-out and very good matrix bond to the glas provides excellent resistence to delamination."
hey glenn . the contour mat isnt really needed …
its just a quick easy way of reproducing bottom contours on any board , with out the need of a highly skilled craftmen or shaping machine …
what mrj and sabs said is right …
you can still shape bottom contours and still use a bed as well tho …
use your deck off cut , cut the outline in your board , shape the bottom , then press your flat unshaped deck against the deck off cut acting as a bed while your forming on your bottom skin , with a bit of jigging you can still put your rails on at the same time , its just takes a bit more planning …
when you go to form the deck on , do it mrj’s way , by bagging and then placing the whole job on your bed and weighting it down …
fiished pics of that board by the end of the week , i finish coated one side today …
ready soon …
regards
BERT
OK - I’m pretty stoked. Sabs full veneer looks every bit as nice as the professional veneer Surftechs. If I was able to get full length sheet and wanted to wrap the deck and rails, I suspect I’m going to run into problems with molding the compound curves without splitting the veneer. The perimeter stringer makes sense as you could overlap on to that and let the stringer serve as a transition point for the edge of the veneer. I read above where Bluejuice uses a heat gun to preform the PVC foam prior to vacuuming. This makes sense for PVC foam. I’ve also read on other sites where foam panels get a criss cross cut on the backside to facilitate wrapping around compound curves.
Has anybody thought of using this stuff (see link below) to soften the veneer before wrapping? It supposedly temporarily plasticizes the wood. Maybe wrap plastic sheet or bag around blank, lay softened veneer over blank, wrap some tape to shape it and after it dries, go ahead and vacuum to blank with resin and glass. Would it affect structural integrity or does wood retain it’s original strength?
The link has a photo of veneer being wrapped around a pencil(!)
http://www.joewoodworker.com/catalog/product_info.php?products_id=616
JM
I was thinking you could roll the veneer up in a tube and steam it just prior to bagging.
use the tape to hold it in place but then bag it while it drys that will give an even better fit for the top skin.
waaahoo - Good idea but I’d be a little concerned about trapping moisture or having the wet wood affect the resin.
4est - Another good idea. I wasn’t sure if wrapping in plastic and vacuum bagging would interfere with drying process?
Bert/John
I’m been blessed to have the opportunity surfgearhawaii teach me the craft in person this week to help me build a christmas present for my sibling. Unfortunately my first project is the hardest shape you could try this on and we’re bending the balsa around the rail and twin noses using blue tape and the vacuum.
Although I haven’t ridden a finished one yet I’m very much impressed with the simplicity of the technique and fact that I’ll have the both the beauty and strength of 1/8" balsa wood veneer and epoxy over a lite EPS shape. The fact that this is all going to happen in 4-5 days from scratch is almost impossible to believe.
The possibilities seem endless with all the materials you could bend and epoxy to the top of a finished EPS shape. Aluminum, polycarb sheet.
Bert how does the Divinylcell compare to balsa in strength? It was very easy to work with and manipulate to create the shell although real tight complec angles are impossible.
I don’t think things will be the same for me anymore regarding boards. I can now envision my dream performance boards all in wood veneer lasting for ever.
I owe so much to surfgear for his kindness in showing me the ropes. I only hope I can do this on my own one day soon still need my own work area.
Bert/Greg
You were so right this whole board building industry pro and backyard has been such a scam. We all nee dto educate ourselves as to what really can be done and at what cost.
Aloha from Hawaii
good news oneula,
divinycell doesnt compare to balsa for strength …
gives a dead ride as well in comparison …
the only reason i used d cell in the vac forming thread was to show the principals involved , plus having a super light version of each construction , my customers can clearly see which one is better …
d cell is more suited to production , readily available , known size and density …
even tho i have a great balsa supplier , there is still a huge amount of variation in density and grain , so while i can get good consistency with my methods … every now and then a magic board pops out because all the right pieces of wood came together for that board …
it certainly is a con indeed …
less wood , less soul …
wood gives the board a feeling of being alive and in tune with the rider …
even tho i might make sandwich variations for different customers …
the day i stop riding balsa over eps will be the day ive found something better …
and for the last 13 years i havent found it …
ok heres a few pics of the sandwich board in the thread …
i havent finished it yet , i was supposed to cut it back and polish it today but i ran out of time , i wont be posting for a few days , so i thought i would show a few pics of the nearly finished article , i did a simple colour job to highlight the natural features of the board , ive never been much of an artist in the sense of artwork and colour … but it suits me …
finish and surf it next week , not that happy with the weight …
2.7 kg or 5.94 lb , explain my mistakes later …even tho its heavier than i wanted it its still at least 800 grams or nearly 2 lb lighter than the lightest possible p/u p/e combo , only difference is , its about 10 times stronger , i can squeeze as hard as i want and cant pressure dent it …
how could you go back to something that dents every time you look at it , self destructs with use , and decays with water and sunlight , surfs like a wet sponge and starts to feel lifeless with age as fatigue sets in …
it certainly is a con my friends …
there is this mentality that if the best surfers in the world are using it , it must be good …
WOW!!! i just realised why board builders have to give boards to pro surfers …
if they didnt get them for free , they certainly wouldnt buy them if they had a choice of buying something lighter and stronger …
of coarse you would ride something you have an endless supply of , even if its free , rather than pay for something that will perform better …
whats the real cost tho???
a potential world title ???
its only a matter of time …
the cats out of the bag …
regards
BERT
Bert -
That board turned out really nice! So, you’re pretty stoked on balsa over EPS - better than PVC over EPS. You’ve already given up a lot so I hesitate to ask but here goes…
I assume that you have access to full sheets like what Sabs used on his first veneer that was posted. Have you tried full sheets? Do you think there is much difference in the various species of wood veneer available as far as strength/weight? Do you think that a full panel would offer better structural support (due to continuous grain) then pieced together smaller pieces?
How much of the spring you describe do you attribute to the stringers?
of coarse you would ride something you have an endless supply of , even if its free , rather than pay for something that will perform better …
I don’t think free boards are that cheap if they end up costing you heats. In several the wct/wqs events this year a couple of guys lost heats due to equipment failure, I think it happened to Taj Burrow and Bruce Irons, what events I’m not sure. These guys ride this superlight equipment to get the performance the judges like, but what’s the point of using these boards if there’s a fairly good chance they’ll snap and they’ll lose the heat.
Pros are scaredeecats! Follow Bert’s advice! Buy Greg’s epoxy! Don’t ever assume that pros understand equipment. I work with millionaire pros for a living. Simon, MR, and Cheyne are exceptions to the rule. They were forward thinkers in their pro heydays. I get the honor of working with two of these three fine fellows.
Follow Burt’s clues and you can become the most sought after craftsman in your zone…you’ll even be able to sell lots of Tees with your logo! Bert and Greg just handed out a really nice Christmas gift to anyone with a little ambition. Randy French is the offensive lineman who just opened a big gaping hole for forward thinking craftsmen to charge through. Hail the pioneers of now!
Love, Delbert Pumpernickel
I just got back from the beautiful monkies, crocs, beans, and decent humans of Costa Rica. I’ll send you a blip Bert.
Hi John
Just to set you straight,the first veneer board (red beech) was made using ‘fitches’ these are veneers straight from the log they vary in width and the edges are not trued up
These come in a ‘pack’ which is all the slices from the log stacked on top of each other
With these you have to true up the edges and cut off any knots etc then tape join them,they are usually around the 3 meter length
You can get ‘layons’ these are fitchs tape joined to make a sheet,so are slighty bigger than 2.4m x 1.2m , the hard work is done for you.
Some lay ons are spirally taken from the log so are the full size with no joins
The only balsa i have so far found is from model shop suppliers ,these sheets are quite small at about 900mm x 100mm
When joining these I did a small scaff at each end using 5 min epoxy,then taped the sides.
I found that the balsa was quite expensive ,and shudder when I think back to when we sailed thru the San Blas and Panama regions ,where we allways found balsa logs some up to 30cm round and 5 meters long on our beach walks with the kids.
Regards Mike
Mike - Thanks very much for that explanation. Do you think full length veneer is better than butted or scarfed pieces? Did you use any kind of softener to allow for rail wrapping?
hi John
The full length veneer is easy cause you dont have to scarff it,but its a lot thinner so you need to look at the high pressure areas ,knees etc
Also because the sandwich is thin you will need a stringer or two perimeter stringers
I did not use any thing to soften the veneer,I did use three strips to go around, each strip was feathered before the next went on
When you sand all these down the joins do not show
It ant easy tring to bend it all in one go as there are two different curves going on at one time,which is why i went for the strip option
Regards Mike
Hey Mike
I’m really inspired by your balsa creations…definitely gonna give it a go myself - but am really uncertain as to how you got the perimeter stringers on.
Coupla questions -
1–Did you trace the rocker line on to your balsa and cut it out - or did you bend long straight strips to shape?
2–Did you vacuum bag the perimeter stringers…directly on to the board or did you put a layer of glass underneath?
Hi Mike,
When you say you use 3 strips to go around I asume you are talking about the perimiter stringers. In your picture it looked like you glued those on on a rocker table using clamps? I’m building a model with my son partly for his school project though my ulterior motive is so I can figure out what I’m doing with vacuum bagging before I waste a lot of materials. We’re both learning and having some fun. Did you made the perimeter stringers oversize and then plane them down?
BTW I found a vacuum gauge on trade me nz for a reasonabel price. Thanks for the info though.
Jon
so bert,
can you do channels bootom with a vacuum construction?
thanks
and thats the finished weight…
i ended up making a few mistakes that i just couldnt make up for in the long run …
the most cricial one was when i glassed the deck on the outside , coz the board is 22" plus wide , i didnt have any 4oz around wide enough …so i glassed in 6oz …
i lost a fraction of weight there …
but because i was conscience of making it heavier , i strained my deck to much …
that was the biggest mistake , i ended up getting heaps of pinholes on the deck glass job …
after i sanded the board it weighed 2486 grams …
but when i finish coated the deck , it all started going wrong …
i kept loading the clear on so all the pinholes would be filled , after i loaded it with 2pac it weighed over 2900 …
i should have sanded the lot off , but i didnt want to respray the artwork …
as you can see i still managed to cut a fair bit from the 2pac finish , but because of the artwork , i was babying it so i wouldnt burn through into my artwork on the deck …
i could have knocked another 200 grams from this weight had i just gone the 4 oz in the first place …
but hey thats life …
hey louis …
any contour is possible …
it just takes planning …
yea john , balsa is definatly my preference as far as performance , plus strength to weight ratios …
ive probably used about 45 to 60 different timbers at a guess over the years …
my opinion is balsa , western red cedar and fiji cedar , give the best strength to weight and performance of the timbers ive tried …
i havent used pualonia or bamboo …
both which also seem to have potential …
with the pvc skins , the weight is almost as good as my woodies , but the ride is different …
a little weaker in the denting department with pvc , theres something about the timing of the flex return with wood that justs makes it feel that bit more natural under your feet in comparison to the pvc version , even tho the weights are similar …
enjoy …
happy hunting …
its cat season …
regards
BERT
