trent,
You are right, in trying to make a point I used windsurfers as an example and shouldn’t have. I haven’t touched one in many years as you suggested, I have only seen them in websites and in person at the local paddleboard shop. But in your reply you did prove my point, and that is that the Surftech looks flimsy. Check out the attached photo!
UPDATE - Check out the “new blank” thread to see what an epoxy sandwich board of the future will look like…take your pick - Greg’s or Bert’s
That photo is a surftech?
I don’t see any foam in the sandwich, just a thin veneer?
Windsurfer sandwich cutouts I saw at a shop had one and sometimes two layers of I think 1/8" pvc foam over the eps core. I think that probably makes them very stiff, though.
trent,
Frst cross-section is tuflite - divnycell.
Second cross-section is a JP High-wind wave board.
Also the Cobra boards are molded core and HAND skinned - aren’t most of the sailboards made in mold completely?
Daddio,
Those are all pictures taken from www.boardlady.com . There is some great information there about this type of construction that anyone interested in it should check out at her site.
My question, is it known for sure if Tuflites have glass between the PVC shell and the EPS or is the PVC just vacuumed direct to the EPS with no glass?
Here is a guy that gives an overview of his PVC vacuum bagged method: http://www.ecboards.co.uk/index.htm
Glenn,
I don’t know the answer to your question about glassing between layers, but I think that we should get the forum headed in the direction of cutting eps with a hotwire cutter.
You know, that big block of edro eps that you want to purchase?
Also when Bert starts puking his guts out about the sandwich construction techniques, we’ll at least have our foam cores and internal floating stringers ready…
poke around here: http://www.demandproducts.com
to see some professional applications…
If you have an old Lionel train transformer you can use that to heat a guitar string…
daddio
hey just wanted to add my limited experience…
i was given a 9’6" fake wood yater like the on that is broken in the photo… it was probably built in the first year or so of surftechs and i have nothing but good things to say about it, i have beat on it pretty hard, road it on big days, shared it with friends, done large floaters and after about 4 years now it still looks new… but i have to say it is too light, if there is chop on the wave face and the wave is large the board bounces out of control…
my second expereince with a surftech has been a continual ding repair job for a friend… he bought 6’6" fake fish at the begining of summer and it creased withen a months of crappy south shore oahu summer surf, no real swell, also it has about 10 “every day” type dings from what i would call very noramal light use and when i repair it, the skin seems sooooo thin like an eggshell…
would i ever buy on? no the main reason being that i have also alot of dealings with Cobra boards because of windsurfing, at $1600 windsurinf boards are a bit more $$$ so i woould expect a stronger better built product, but… they fall apart fastter then the surftechs…
If you have an old Lionel train transformer you can use that to heat a guitar string…
I think the “transformer” is the key word when thinking of a power supply for a hotwire. I have looked on the web and some people say use a regular light dimmer switch to control the power to a battery charger. Like on this page here is the dimmer setup you’d plug your battery charger into: http://www.oldf.homestead.com/foamcutting.html . You’d then use the alligator clips from the battery charger to hook to your hotwire. But is not a battery charger just a transformer anyway that converts 120vac into 12vdc at the amps specified on the charger? Then there are those that say it is best to use a “variac”, but to isolate it with a transformer as well. What I read about the variac is not to use it without an isolation transformer. The AC current that could be drawn from it if you were to accidently ground yourself while touching the two wires would put you to sleep, because you could potentially draw the full current available from the wall outlet. Also from what I’ve read is that when using a variac you can put the transformer before or after the variac. Here is a page that shows this setup: http://www.public.iastate.edu/~orman/air/cutter/page9.jpg What I’ve gathered is that the variac setup would be best because it can power a longer wire more accurately. Variac’s on eBay can be had for a fair price, the trick with this setup would be finding a step-down isolation transformer that is 24v-30v at an amperage of 10w. My understanding is that you need the amperage, most that you see on eBay are low amperage. But this setup would mean a little more cost because most don’t have a variac and a 30v-10a transformer just lying around. I hear some say Nichrome wire is best others say stainless steel wire is best. But I’ve also read that the wire can stretch pretty good because of the heat so proper tensioning is key. I’ll find out in the future… I’m gunna mess with my battery charger that I’ve got for the moment on some scrap eps to see how that goes before I mess up a large block of eps. Greg said that he had some information for me on hotwires he’s going to send me too.
Glenn,
Here’s how the block will be cut with the hotwire. The following link, although not related to surfboard building, does show a simple hotwire set-up and how to use two matching “templates” on either side of the block of foam to cut out a shape…
http://www.vatsaas.org/rtv/construction/hotwirecutter.aspx[url]
Yes that is how I was thinking of doing it too. I found this site that shows the cutting of a block of eps: http://www.ecboards.co.uk/board_chapters/public/chapter4.htm
Great links!
Please repost all your pertinent info in a new thread. I think this title “surftech’s” would be confusing if searching in the archives? I really think that a lot of people aren’t saying much right now, but when Bert starts talking about the foam sandwich and balsa sandwich construction techniques there’s gonna be an explosion of new ideas. Bert’s had a head start and once we’re all up to speed I envision some quantum leaps in the surf industry taking place. When Greg’s blank is available to us as well, my oh my…
A regular 12V battery charger with a 2’ nichrome wire works just fine. It doesn’t take more than a couple of minutes for each side of board. If you can’t wait that long, maybe a transformer is worth the money.
regards,
Håvard
" Surftech definately has some good points. The people here knocking them are in the board building business and generally have their own vested interest. … In closing, to the industry, stop all the bad mouthing and DO SOMETHING ABOUT IT!. Raise the bar…" … amen to that ! Well said Greg…most people I hear and see knocking stuff like surftech and salomon for example have not even TRIED, and in many cases even SEEN the very thing they knock. Their ignorance is there for all to see , their credibility zero… chip
……I’m gunna mess with my battery charger that I’ve got for the moment on some scrap eps to see how that goes before I mess up a large block of eps. Greg said that he had some information for me on hotwires he’s going to send me too.
Cutting scrap eps will be worthwhile in experimenting with the temperatures that produce the cut you like. But keep in mind that unless the experimental cuts, and your final large block cut(s), have the same length(s) of wire exposed to the foam the voltage/current/wire temperature characteristics will change as the contact of the wire with foam cools the wire more than contact of the wire with air.
I used a battery charger. I messed with wire guages until I got the right amount of resistance. 20 ga. (stainless steel) didn’t get hot enough with the charger set at 6v/10A; 24 ga. got too hot and stretched too much and made wobbly cuts. I finally found that, over my 26" wide bow, 22 ga. ss wire was just right.
wo , wo , …
easier way …
get your phone book out …
look for polystyrene manufacturers …
ring them and find out what file formats they want so you can give them the information about what shape you need hotwired out of eps …
get a curve program , design your rocker thickness , give the information to the foam cutting company in the desired format …cutting the foam is included in the price…you pay by the cubic meter …
they can design a curve for you if you give them points , but theyll usually charge a programing fee , if you go that way a few of you may need to pitch in for a block or two …
no mess, no fuss , perfect cuts , any density you want , youll have exact rocker information either on your computer , or a printout you can get from them …
in the early days , i would give the information to a guy over the phone , give him rocker and thickness co-ordinates , i would then get something like this posted to me , to doublecheck…eventually it got quicker with a faxed image , then the internet appeared and it got even easier , these days you can just email rocker files straight to the foam company , as you already know the look of the curves you designed on your own computer …
try that one …
regards
BERT
