I finally have all my tools built and I’m ready to start my first T-Flex / Compsand. First question is; Does “T-Flex” refer only to boards with a veneer of some sort, or is it a catch-all term for the process used in building with this tecnique? I ask because I plan to build a few boards with and without veneers.
So, with that in mind;
What is the best desity eps to use in this process.
Would 2# under veneer be too much? And what about without veneer?
Also, would stringers be necessary with and without veneers?
I was planning on cutting my blanks from a billet of Insulfoam. I got a quote from their warehouse of $169.00 for a 24" x 96" x 36" block (2 lb. density). Has anyone used this brand of foam for boards? I live in Everett, WA and the Insulfoam warehouse is about 45 mins. from me, so that’s handy.
Finally, is there even a reason to vac-bag the boards that won’t have veneer skins on them? Or just glass as normal?
Thanks for any help and answers to these questions.
I’ve used 1.5 and 2. Both are excellent. I haven’t used 1# with T-Flex because it’s a hassle having to reenforce boxes and plugs and 1# also breaks easier and leaks. For a quarter pound weight savings … no thanks. You can certainly build 2# boards without veneers but the veneer boards are far stronger and are better performance.
stringer optional, depending on the size of the intended waves…it’s just going to complicate your build, especially considering the fact that you’re talking about cutting your blank out of a block of foam.
if you go with the local foam, you’re going to either have to hotwire your rocker in to it or get a rocker bed.
you will get more out of that 3’ tall block if you cut your foam flat and put the rocker in to it on a rocker bed/table, vacuuming on the deck veneer with epoxy to keep the rocker fixed.
you could 2# with a solid glass schedule and you wouldn’t need a vacuum bag, but this assumes you’re cutting your rocker in to the blank itself.
fiberglass supply is in washington…not sure how close they are to you though…
You know I’ve done 2# bending the blank in a rocker bed and I’m not a fan of that one. You get some sping back with 2# … at least I always did. Especially if it’s good stuff. Working with Bert we were doing 1# with corecel on the bottom and the balsa rails and we were dealing with some springback there even. And also bending the foam you get a pretensioned core which is NOT good.
To me there’s nothing like shape and glass … well shape, bag and glass.
Silly, it depends on your composite. 1# will break easier in a T-Flex than 2# … for sure. 2# EPS is still lighter than urethane which is 2.5 to 3# density. And urethane delaminates under wood eventually … EPS doesn’t. Glassing with polyester resin will cost you another 1/2 lb in weight. Good 2# EPS doesn’t suck water. 1.5 either.
I do feel for you guys there … materials are so expensive and difficult to get good stuff. You guys do incredible stuff with what’s available.
I just pulled a EPS, 1# balsa skinned blank out of the bag yesterday. No stringer. I hotwire my blanks now and use a rocker bed. I haven’t broken one yet, but give me more time. I find 1# easy to shape, but it is fragile stuff until you get the crust on.
Nice work pompano, looks like you got some time to get back into things.
As for the t-flex, seems like you can use whatever foam you have available to you, just adjust the glassing schedule accordingly. Denser foam, use less glass, lighter foam use more glass. There’s probably some combinations that work better than others as GregL has mentioned, but they should all work.
Stringerless, single-density blank seems like the way to go for simplicity and ease of build.
Thanks for all the feedback guys. It has cleared alot of things up for me.
The concensus seems to be that 2# eps will hold it’s rocker under a vac if I hotwire the rocker out of my block even without a stringer. That’s good news for me. I had considered building a rocker table if I needed to, but that would complicate and elogate the whole process. I see the benefit of hotwiring out flat sheets and bending them to save foam, but for me some “wasted” foam is a fair trade-off for simplicity of build. I could save the bottom cut-out from my block and therefore have a foam rocker table of sorts.
Afoaf,
Fiberglass supply is about an hour’s drive north of me. Had considered making the drive for my glassing supplies. I found a local place, Fiberglass Mart, who seems to have good pricing. Looks like they carry West System epoxy. He’s got cloth by the yard in 1.5oz., 4oz. and 6oz.
Thanks again guys. Once again your advice and expertise is invaluable.
the idea is that you get a great rocker. emphasise the nose flip a touch. cut the rocker table out of eps then you have that table for all your next boards. its actually just as easy to bag a board on a eps table as it is to bag a board. you slide that whole lot in the bag. then you can just buy 50 mm insulation sheets and waste is neglible.it is the way to go if you have a good rocker then you can play with the variations of thickness ,build schedual and fin setups to find the ideal recipe that can compare with a well made PU board. composite boards are overated IMO . a well made pu is a pretty durable board. composite boards are stiff and corky . most of the composite boards i see made on swaylocks i can see they would be more fun boards and not performance boards. as they are looking too thick with corky rails and odd rockers. i dont think anyone is doing composites faster then huie or me and we both use rocker table. using heavier foam defeats the purpose of a composite skin, just stick on some d cell on a poly blank and glass it with poly you will have a similar result. heavy waves will snap any board including a heavy built composite.
you guys dont seem to get it . composite sandwich. its the** core** material between the glass that makes the difference
timberflex and compsand are two different animals although it get confusing due to warvel using the the compsand word.
the heavier cores and thin veneer derive more strength from the eps core, where compsand derive there strength from the skin material core
timber flex veneer is like .5 mm in a sandwich
compsand is more 3 to 5 mm in a sandwich
composite strength is linear . a 3mm sandwich is potentialy something like 6 times stronger then a .5 mm. although i dont know maths .
2 pound eps is only moderately stronger then 1 pound eps in real world testing . like bending a piece. in fact i rekon 1 pound is actually stronger cuz it bends further without breaking. if you increase the density of the eps according to composite rules it will increase the stiffness of the board. thats why they need to use thin veneers or the boards would be stiff as fuck.
Silly, you’re correct. The core material does make all the difference. You seem to be speaking exclusively of compsand boards whereas this thread kind of meanders all over the place as far as build specifics so a number of different construction types have been addressed.
I wouldn’t use 1lb foam for a stringerless Coil style board and wouldn’t use 2lb foam in a compsand for the reasons you mention. The composite skins are carrying the load so the core is just filler seperating the skins. In a timberflex or coil board the core needs to carry more of the load so a 1.5 pound core works better. I’ve got a 2lb stringered blank with 6/6/6 glass and it’s help up great for nearly 4 years of abuse, so that combination obviously works well.
None of these are meant to be blanket statements, the construction method must be taken into account.
You do have a bit of leeway in the glass schedule to account for a higher density blank though. It’s not an absolute. A 2lb core could probably work in a compsand if you made the skins 0.5 thick. Just because you’ve got it dialed with 1lb core and 3mm skins doesn’t mean someone else can’t adjust the recipe and make it work for them.
I wonder what would make a bigger difference in stiffness, blank density or the thickness of the core? Say a 2lb blank that was 1 3/4" thick versus a 1lb blank that was 2 1/2 thick. You can adjust variables to account for your methods.
In typical Swaylocks fashion I’m totally talking out my ass here as I’ve only ridden Coil boards, stringerless 1.5lb eps, and 2lb eps w/ stringer. I’m having a t-flex style board built currently with 1.5lb eps to try that out. So I’ll have to take your word for it on the compsand approach.
For the sake of anyone who may make the unfortunate mistake of reading your historical posts, perhaps you should go back and edit all your posts where you emphatically claim Gorilla Glue is the second coming (and then it’s total shit), or that skinned boards are the only way to go (but now PU/PE is) or that wood rails have the best pop…then HD foam as the best pop and then…composite is the best (but now doesn’t seem to be).
Your posts the past couple of months appear to be a nearly complete 180` on everything you fought tooth and nail over for the preceding few years…why?..because it’s faster/easier for you to build pu/pe for sale or because you truly believe that the home builder won’t benefit from the composites construction.
I don’t know if it is comical or depressing that the loudest and most ornery proponent for composite is now consistently talking about pupe as the new target…am I the only one?
Aren’t Greg’s T-Flex boards just a type of compsand? If you want to get really specific aren’t all surfboards with a core laminated in fiberglass a compsand. I know I am stealing someone else’s quote, but there are lots of ways to skin a cat. I may be wrong, but I do not think you need to vacuum bag and use 1 pound eps to call your board a compsand.
Ah yes the ole poopee v. compsand debate…still goin strong after all these years.
Havent been here in a while and just noticed Silly’s newest take. I remember the old compsand.com arguments he and I had. My take has always been compsand is the most advanced, poopee is the most profitable. Good on ya Paul, I dont blame you in the least. Its a dog eat dog world out there and you have a family to feed.
Afterall, they’re just surfboards. Make or buy what gives you the most enjoyment.
