Have you guys called the Dow customer service number on their website? I did, and they gave me about 5 different suppliers within a 50 mile radius. I ended up getting mine from Foam Sales & Marketing in Burbank, CA. They have all the sizes up to 4" thick.
I glued up 1" thick and 2" thick 24" x 8' sheets of insulation with the ends of the sheets propped up to provide rocker. Used Elmers glue between the sheets and put heavy weights (paint cans, cinder blocks, wood, and power tools) on top to hold all in the bent position till dried. Worked fine, but Elmers took a few days to dry between the sheets where no air was getting to it. Regular Home Depot insulation foam - Owens Corning brand. The pink color is the main draw back so far... though I should say it is also harder to shape than Clark/PU foam. Eric J
hello Eric, the imagination can create some bad case scenarios, like you suggested my board doesn't seem to be any of the large foam eaten cavities which I feared. I've been trying to analyse why a flexy reverse lapped blank might warp tho and maybe if curing lam shrinks then with little rail lap it might bow out the rocker even more - just guessing don't know about this. Your CF strip seems to be an alternative to putting a stringer in. I've personally found out a long time ago that a handsaw although fine for an outline doesn't do a good job of splitting a blank down the center and my hot wire isn't long enough. If I was about to lam xps/expoxy again my concern would be blow-thru leading to pinholes. I've been analysing this and wonder if the following might work: 1. Leave the curing lam until just after it has reached its peak temperature - not sure when this is, epoxy does get hot. 2. in theory all the blowing agent gases that were going to expand would have been expelled now and we can aim for "suck-in". So at this point do a baste over the non lap regions. the multiple overlaps on the rails are less prone to pinholes and putting a layer of baste in between the overlaps would be bad news anyway. what does anyone think about this? About your concerns of the paint reducing lam adhesion I think from looking at the texture of xps, that being similar to clark a mechanical bond will be achieved so provided the paint hasn't gone on really thick nothing to worry about. The bond between polyester and polyurethane foam is mechanical, although future boxes say they get a chemical bond with poly or epoxy so don't paint the box flanges. But I remember you foam stained the centre - you didn't paint over that did you? ps I've uploaded some pics of my project onto the surfline forum. I'm going to try and get a better pic which illustrates the shape to submit to swaylocks resources.
test session 4 took place early this morning. I arrive in the car park and can't see the martial artist although I think I recognise his car. Nothing unusual happening this morning or maybe I'm getting used to the place. My concentration is on the surf which appears to have improved. Can see a couple of black dots in the water thru the fog. One of the dots catches a wave and stands up - ah other surfers today. Put on my 4/3 wetsuit, step over a large roll of carpet and onto the sand. Avoid a broken bottle and I am on my way to the sea to implement the idea I had at the end of my last session. I'm not performing the usual pure twinnie control session today and already my board is in a tweaked mode. The left side of my board is supercharged and the right side normally aspirated! Yesterday evening I hacked away at the unwanted trailer fin with my dremel tool. Its been reduced in height and width by about a 1/3, reducing its area considerably. I've tried to copy the shape of the superchargers shown in the photo archives and placed it in the left twinzer box and it is just over 2 1/4" tall. Its had its outline shape reduced evenly to maintain the centralisation on the leading edge of the main fin. It looks quite small. I'm regular foot so in theory the supercharger will kick in when I'm going backhand, performing frontside cutbacks and performing frontside off the lips. Unfortunately the fog had been playing some tricks with my imagination and wave utility was slightly down from last time. Some occassional bigger ones, less wind but the consistency was down. Maybe the tide was a bit low. Still good fun though and my board is the perfect choice for this stuff. Unlike my other tweaks this one is the most subtle. I think I can feel it project and drive more on the lefts. It seems much the same on the rights, maybe its coming off the top frontside better but I'm not sure. Maybe its a bit stickier in the frontside cutback but I'm not sure. After almost an hour I leave the water briefly to switch the position of the supercharger. Its foiled both sides so I can do this and sits upright and doesn't follow the cant of the main twin fin. So now I'm supercharged frontside and normally aspirated backhand. I think I can tell the difference going right (frontside) - it does seem a bit stiffer into the bottom turn. I'm not sure if there is a speed difference. I fly along on a lefthander, confounding my thought that it was helping me project better backhand in the first part of the session. On a frontside wave I throw in a cutback and feel that twin fin slide. Something I didn't experience with the supercharger on the opposite side. I don't mind the controllable drift of a twin doing a cutback though. hmmmm???
On the paint adhesion - yes I painted over everything - even the areas that I tried the foam stain on. so there is an epoxy strip down the center of the boards deck (over the CF) that might tend to delaminate and a little on the end of the tail. I'm going to scuff up all the paint well before glassing it and hope for the best. The paint is a thin coat - the texture of the foam is still very evident except for directly over the strip. The CF strip was an alternative to putting in a stringer. I have a table saw so I could have made a straight cut... But it seemed uncecessary and the CF strip will, hopefully, provide some strength and spring that the stringer would have. We'll see. The future boxes and the FU box were epoxied into the foam before the paint job. Futures will get lammed over - with patches added - and sanded down to expose the slots. FU will also get an overlay of glass to help hold it in. I did not slop paint onto the box lips and will take off what I did get on them to help the glass bind to them. On twist - I think I've heard here that one cause is not keeping the weave of the cloth straight when laminating and uneven lamination (more resin on one side of the deck than the other). So there is tension in the cloth which is accentuated with the uneven curing of the resin and it can pull one rail up at bit. I thought a reverse lap is supposed to help avoid this problem, but it would seem, if there is enough tension created in curing the resin, either revese or regular laps would warp/twist. Life might actually allow me to get into the water this weekend. If so I'll be a new man on Monday.... though the pink project will still be on the racks. Off to do some work now... EJ
Hello Eric, hopefully by the time you read this you will have had some waves. My blue board wasn't used this weekend, instead a job for one of my professionaly made point break boards. About our boards: I was literally panicking when my hot coat seemed to go wrong, but mustn't let the resin fumes make us neurotic. Despite my less than perfect glass job my board seems to be holding up fine. I would also go as far as to say I'm delighted with the results and not too worried if the construction starts to fail. As anyone who has been following my posts would have realised I didn't entirely know what I was doing, and therefore likely to produce unpredictable results. But that was part of the enjoyment. If my board does start to come apart then I'll post the symptoms so that we can all learn. Our boards both have a fairly solid glassing schemes so they aren't going to disintegrate on contact with the water. It takes a lot of surfing to send a board to destruction. There was a thread on spraying in between the hot coat and gloss which may be relevant, but I'm not sure if its necessary to scuff the paint as epoxy is good at sticking to things but other things aren't so good at sticking to epoxy. To prevent ppl having to wade thru the entire thread and weed out all my off topic verbage I plan to confirm my design findings with more beachbreak testing and then post a summary here. But apart from that and any possible durability reports thats it for my blue xps project. Swaylocks is a great place and if it wasn't for your post at the top of this thread Eric, where you described your rocker glue up, my project would never have got started. I'll be monitoring this thread for any sign of activity in your shed :-)
Thanks Mr. J. Swaylocks is a great place indeed. Glad you got a surf this weekend - I did as well, proving that I'm not in the best surfing shape! but with my work and a few family members in and out of hospitals in recent months there has been little opportunity. Things are freeing up now though. The pink project waits for glassing. I hope to get to that next week. I'll post back when I've been able to do more work on this. Glad that blue board is working for you. In the words of Herb S.... 'Keep building!' EJ