Latest project -10’6" long, 3 1/4" thick, single stringer polyurethane blank with RR epoxy resin.
The surfer weighs 224 lbs.
Are 2 layers of 6 oz on the deck sufficient to prevent pressure dings? ( 1 x 6 oz on bottom)
Trying to keep weight and cost down.
Funny how such a thin layer can offer very good ding resistance resinhead. My mate snapped his on a large day, and as i saw one half wash up on the beach ( while catching my breath after being flogged again and again ), i had a good look, and the top layer, between the inner foam and deck, which was orange, was maybe 1/8?, but his board had, and still has ( he got it fixed, still goes great ) hardly any dings.
I’m a big boy weighing in at around 200 but usually fluctuate between this and 220. I find epoxy which I’ve been riding for years along with PU/PE. to be more durable and lighter in combinmarion with EPS foam. Since you’re using triple stringer PU foam I’m sure you will not have issue with weight. If I were you I’d lay down a 6oz deck patch and the same around the fin and keep the laps wide. That should be strong without going in to S cloth volan combinations.
Fuck yeah!
When you say 6 oz deck patch is that on top of the 2 layers of 6 oz? I not experienced in deck patches. I have always been wary of them because I feel they would affect the flex of the board. I also not sure where to put them. Rear third? If 2 x 6 is not enough then is it not better just to have 3 x 6 or 2 x 6 + 1 layer of 4 oz or just 3 x 4 oz?
Last year I made a board with 2 layers of 6 oz on the deck for a 230 lb chap. The reason it has no pressure dings on the deck is because he hardly ever uses it so thats not much help.
Three pieces of wood will affect the flex more than any a patch or not. Just put a a patch over the area that is the most dented up on his old LB. Cut it in a diamond pattern to avoid breakage. 3x4 or 3x6 will be stronger but you want it on the cheap and light right?
Its single stringer not triple. His current board is a Surftech but I will have check with him his previous experience of deck denting on PU boards. I only have enough 6 oz cloth for 2 layers on the deck so will need to order some more 4 or 6 oz for the patch. Surely 4 oz would be sufficient and use less resin than 6?
IMO epoxy dents more than it cracks under a heavy foot. I did 2 layers of 4oz plus deckpatch in epoxy over PU once and it dented pretty good under a 190# rider with a heavy foot. Depending on who you talk to that 12oz combo is arguably stronger than 2 layers of 6oz. IMO you need at least a deckpatch for a 220# rider.
The unknown variable in your description is how your rider (realistically) intends to ride the board. If he’s capable of walking the board and noseriding then I’d want to extend the deckpatch to the nose, either as an inlay or as a complete layer with laps. On the other hand if he mostly camps out over a 2+1 fin cluster and rides off the tail then a deckpatch in his impact area might be sufficient. If it was my project and I were doing a deckpatch I’d shoot for 2 layers of 4oz set at the opposing diagonal bias and I’d use warp if its available. The difference in weight won’t be but a few ounces but the results would be worth it (to me).
From my research and talking to others I have no doubt that 3 x 4oz is far stronger than 2 x 6 oz. For my own boards I have traditionally and habitually used combinations of 6 oz because it works out cheaper and at 13 stone have not had a problem with denting.
I use Hexcel cloth thats 80cm wide so I dont know how I would achieve opposing diagonal layers in one piece to maximise strength. I presume I need to look at a different type of cloth?
The Prime Directive for us backyarder types is to use what we’ve got, ya?
I have a friend who suggested tacking a corner of the cloth down and pulling on the opposite corner to pull the bias diagonally for a deckpatch. I’ve never tried it myself, though. Over here we have access to 3.2oz crowfoot in the 60" widths for cheap so I’ve been using that.
howdy
just cut it and put it askew [at 45/-45] yourself
what i would do [based on my 1st experience] is this:
put one layer on deck, glass it, when tacky, but not gluey, lay the 45/-45 on top
cut the cloth on the rails
push down till neat and tidy, sticking to first layer
then, put another layer on top
cut the cloth on the rails
Come on guys were missing a huge question here. what type of foam? EPS, PU, What weight of foam. Is it 1 lb, 2 lb...5 lb. Is it like the old Ice Nine or Warvel foam..If it's that dense you won't need glass.
2lb foam with 2x6 is plenty strong. Also how long have you been glassing..are you a good glasser or is this only board #10?
He's riding a surftech so having a stiff surfboard is not a problem. You could do a 2lb EPS with 3x6 and he would be happy. Jus remember Surftech's use a Dcell foam top over the EPS core. Its bullet proof against compression and blunt force trama. But are stiff as 2x4's and when they fail they explode.
Example of deck and fin patches
I agree with resinhead, the density of the pu blank is a big variable. I am riding a surfblanks america [purple coded high density ] stringerless,9’7’’ 3-3/8 thick glassed with RR epoxy resin. A layer of 6-6-8 onthe deck with wide cut laps. and 6-8 onthe bottom .the board flexes nice and no dents .it is a pig shape and comes in at 26# ,but it fits this style of board. the board has been in the water for about a year. I am very hard on the decks of my boards, and I come in at between 225-235 pounds.So you can ajust this to fit your needs. almost done a US blanks tow foam [very high density] 9’6’’ 3.25 thick stepdeck with 6&6 onthe deck and 6&4 on the bottom .It has not seen the water yet but the weight and flex feel close to the 9’7’'. i think what you might consider is higher density foam and maybe less cloth than I use to acheive your desired results. Hope this helps
The blank is Homeblown PU foam.
Homeblown claim that their foam has superior compression strength compared to most other foams:
http://www.homeblown.co.uk/technology/testing.php
This would seem to indicate that additional glassing is not necessary.
My previous experience of using homeblown blanks with a standard glass schedule has produced good results (for non 16 stoners)
Nice board.
The deck patch is great for the front foot but what about the rear foot putting pressure on the tail during turns?
Should there not be a patch over the fin area?
You could just run it all the way back to the tail though.