Hey Mr.J - i wouldn’t be too concerned with the poly getting in a few pinholes. likely that it would set before it did too much damage. And how much would get through the pinholes anyway? I can’t think too much, but if you are more comfortable with it use the epoxy for the sanding coat(s). If I were out there I’d lend you my sander and shed… but I’m in NY - so no can do. If needed, a good sander can be gotten for very little money at Harborfrieght.com. You can archive some of Herbs posts on these. I have two of the 7" versions (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=46507), but there is a 6" for even less (http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45479). Sanding in your apt. is a little nuts. but at least the epoxy dust is a bit kinder (I Think) than poly would be. Seal the room off and grind away - or, if there is an outside area you can use, that might be best. I’d take down the big lumps by hand with a surform tool first, not as dusty. Then wack down the bigger high spots with 80 grit. That will probably make a huge mess. If that gets everything nice and level, maybe you can do the rest by hand and keep the dust to a minimum? wet sanding, when things get finer, will keep the dust down too - but not sure if it would be too good of an idea to do that inside - with and apartment below you? -------------------------- I tested some colors for foam stain technique on some xps scraps. White Epoxy pigment - in the tube from the marine store with some of the west system epoxy (a small amount just for the test) does an OK job covering the pink - there will be some show through it seems - but it is still a big improvement over the bright pink. Blue pigment (originally purchased and used for polyester resin) seems to work as good, and the foam and epoxy all look fine with this pigment used too. -------------- Anyone - Greg L., Sluggo, etc - know if I’m making a big problem for myself with using the resin pigments labeled for poly with epoxy - it seems to work - but I’ve only tested it and don’t want big delam problems down the road. Are the pigments essentially the same for poly and epoxy? --------------- I bought a few of the clear plastic cups for measuring and eyeballed the ratios to the lines on the cup. Worked fine - and one test involved laminating some cloth which produced a rock hard, sandable surface in 24 hours. Not bad but I’m going to get impatient with this I’m sure. Spoiled by Suncure - but it’s great that epoxy doesn’t smell. The 6’6" twin is (from memory since I’m at work) 17" x 22.5" x 16" x 3.25". Wide point forward 3" (I think). Fish tail - 11" point to point 6.5" deep cleft. Standard twin fin set from Fiberglass supply.com - which look like wide based thruster side-fins set 12" up from the points. flat bottom, low rocker - 3" forward/1" rear. The stringer is 1/4 (not sure of the wood). rails are a little hard in the tail but very soft everywhere else. Rails in the nose are a bit thinned out compared to the mid and rear-end. Blank was canibilized from an old single fat wing-pin beater (a Charlie Bunger, actually the first board I ever owned) That was probably a cut down/reshaped longboard. I got the board sometime around 1978 and it was already pretty beat-up and old. Yes - heartless of me to strip an old classic beater - and my first board - but I like the twin ‘much’ better than the original. blank is colored with tempura paints - my 7 year-old daughter helped me mix the colors - teal bottom, green and blue panels on the deck, black pins on the foam. Suncure lamination - 2x6 top, 1x6 bottom. with a thick sanding coat and then a thick gloss coat. It’s very easy to catch waves on, fast and just plows over and through chop. very loose too. holds and carves when you set it on a rail but can also be slid and twisted around easily when ridden flat - so much flat, not much fin. Whew… sorry for the long post. Pau, EJ
Hello Eric, thanks for the long post, all good information for others who might be reading this thread too. So you also prefer your twin fins further up. My early twin fins had sliding boxes so thats how I established my measurements. Back to concave again - although I havent tried deeper than 3mm I can personally testify that my single concave board does have a controlability problem in solid heavy textured waves and I’ve had it sort of sticking flat to the surface on steep heavy takeoffs instead of engaging a rail and angling easily - however this is a short stubby board , what you are planning has stability compensators. Your suggestion that not much polyester would have penetrated is encouraging and I just read a good article on pinholes on surfline’s shaper’s bay. It suggests that they are “blow thru” caused by warmed setting resin causing lightweight blanks to expand their gas. So I’m hopefull that the polyester would have been pushed out rather than sucked in - the whole lot was room temp. But I can imagine a board warmed in the car and then placed in the cold sea sucking in water. I’m going to seek a professional sander/bay - maybe where I got my last custom board in Cali might do it. I’ve managed to get away without complaints from my neighbours so far and the two layers of poly tarp have kept the resin off the floor. As you have noticed the epoxy dries to a sandable finish - no sandpaper clogging stickiness. I got sb-112 partly coz it claimed no amine-blush thus allowing multiple laminations to stick without sanding - I hope. Its been a great learning process so far. Although the smell is a lot less than poly I wouldn’t take it lightly - I found an archive written by Noodle who had got sensitivity after only 10 boards or so. I don’t notice a smell thru my mask with organic filter but don’t know whats getting thru. A garden shed would be wonderful, but at least ventilation wise I’m doing ok - I’m on the top floor of a narrow apartment and the breeze can flow in thru the bedroom and out through the balcony door on the otherside when glassing.
An uneventful boardbuilding day today. Well sort of. The pigment instructions say that it will work for polyester, urethane or epoxy but use 25% less for epoxy. I’m not in the mood for experimenting after yesterdays events and hot coat with a 8/3.5oz clear epoxy mix . Use about 3/4 of this - hmmm is the board absorbing it or not? maybe just trying to level itself out on the textured cloth is where all the resin goes. Wait 20min for the pot to go into its sticky phase. Yes blow thru is an accurate term I can see gas bubbles emerge from the pinhoes. I pull the tape and go to the office. After about an hour in work a horrible thought enters my head. I put the mixing pot containing the leftovers on the balcony and the sun would be on it by now - even with its long sticky phase epoxy sets with a lot of heat - I have visions of my apartment on fire. I exit the office, jump on my bicycle - 5mins to home if I step hard on the pedals. All is well - phew! Maybe the fumes are making me paranoid. When arriving home in the evening all odour has gone - the balcony door was left open. The hot coat is no longer tacky. The board looks a bit of a joke, a patchy white hot coat on deck and clear on underneath. This can still be an ok board I tell myself. Get it sanded and coloured sealer should cover it all up. On the plus side the shape did come out how I imagined it, my kitchen scales are still clean (a layer of cling wrap discarded after every use protected it), the dining table on the which the blank was hot wire cut and mixing was done is still intact. I had a piece of drywall on the table anyway from when I was building model aircraft and waxed paper protected it during resin mixing. I also took the approach of throwing away my yoghurt mixing pots after every use and not attempting to wash brushes. Nevertheless what I did was not sensible, but no reward without risk. This will be my last post until I get it sanded.
Hey Mr. J - how about taking some pictures and posting them? It could be helpful to show how it looks now and after the colored sealer goes on - unless you end up not liking the color, of course. The shape is (or should be) the most important aspect, and remember that a colored sealer coat can be sanded down and sprayed over until you get it to satisfaction. It can work well. I did essentially the same thing on an old board a while ago with polyester resin. Dressed it up nicely (see Resource ID # 283). A colored sanding coat. Now that board has been stripped, reshaped, and cut down to a 7’7" mini longboard/egg type thing with tiger stripes on the bottom, and (since I cannot leave well enough alone) I may cut it down further and make a nice twin/fishy thing in the 6’4" range. That might be my next vacation project. Thanks for the info from the pigment spec’s you have. Glad to get some confirmation. I plan on doing the foam stain in a few days. White over the pink to start. Then maybe I’ll get more creative - more likely my daughter will make some suggestions that I’ll incorporate. I’ll try to get some pictures of the process too. I need lam epoxy. Time to email Greg L. Glad to hear your room is intact …so far. Eric J
Hello Eric, I’ve been taking pictures of the building process with a regular camera so I’ll get them scanned and post some regardless of the aesthetic result. I can’t wait to start playing with the configurations allowed by the 5 fin boxes. Thanks for referring me to your resource, the streaky abstract finish you achieved gives me some ideas for my final colour coat. I look forward to hearing more from your pink xps project.
Construction resumed today. A fellow Swaylockian responded to my “Wanted:board sanded” advert and offered use of his modified sanding pad which fits in the chuck of an electric drill. (thanks Kim). The neigbour below and to the side of me left their apartments (I could tell from the vacant car spots) so it was a good time to lay the poly-tarp on the balcony and get going. My chunks of foam rocker table were placed on the floor and sanding proceeded. My re-chargable electric drill runs with sufficient torque and low speed, but ran out of energy rather quickly. I managed to get another partial charge out of it and do most of the underneath then did the rails by hand. As I explained before the hull is hot coated in epoxy and the deck in polyester. The epoxy is noticeably tougher and requires more effort but does not clog the paper. The drill is getting an overnight charge and I expect to finish sanding tomorrow.
what’s your initial impressions on the strength?
Hey Mr.J - ‘Things’ came up this weekend and I was unable to work on the pink project at all - . I did take a few minutes to lay some foam-stain stripes on the bottom of a shortboard I had shaped a while ago (another re-shape on an old board that I stripped) and never glassed - yet. That worked fine, except that I mixed the resin batches (epoxy) hot enough that it melted the little plastic mixing cups used for the different colors when it started to cure. Lesson learned. Stripes were done by soaking a piece of roving in colored resin and then laying it over the foam and wrapping it around the rail to a tape edge - then lift and it leaves just a bit of colored resin on the foam where the roving has been (If you do this be sure to let the roving drain for a bit after dunking it in the colored resin that way you avoid drips and puddles). I’ve done this before (in lamination - not on the foam) with clean, white, cotton string - string was a bit easier to handle than roving and soaked up a more even amount of resin along it’s length. Roving is always kinda messy and has a bit more memory than string so it can be hard to handle. Stripes worked out fine on the foam with very little in the way of bump or raised surface along the stripe. I’m going to lam clear over this and avoid having to cut laps. More on the pink xps project when I get some more resin… and I’m going to get film to take a few before and after pics. I’ve sanded with a drill before too… that can be much harder than with a standard sander/polisher tool since the angle of the drill makes it harder to control the pad. Hope all works out well and you get the thing sanded out without too much trouble - or dust. Keep posting more - and if you haven’t - take a look at the $35 board post and link - not quite true at $35. as I’m sure you realize. Eric
when I achieve my long term ambition of owning a garden shed I want to get into all the foam stain and acid splash psychedelic stuff, so your post was interesting. However I’m aiming to be realistic with what can be achieved in my apartment and the main objective of this excercise is to test some of my rocker, twinzer, rail shape and hull theories. Board is now finished and ready for testing. I sanded the board the best I could on the poly tarp on my balcony. The best thing I can do with the poly tarp now is to throw it away to avoid contaminating my apartment with dust and glass strands from the glassing process. My balcony comes with a little storage area which is now full of foam offcuts and other scrap. Acrylic sealer from fiberglasssupply.com seems to stick ok to epoxy or polyester. Very little is needed and it went on with a foam brush and dries for recoat in 30min. I mixed in some blue latex house paint from homedepot for the second coat . I was borrowing from the streaky finish that you achieved. It was just what I needed to cover up the incompletely sanded ripples in the hull and when combined with the sanded patchy white hot coat on the deck gives the board a sort of beat up antique look. Nevertheless I am stoked and can’t wait to test it. It feels strong, but only testing will determine that. The place where boards always go with me are the tail and near the rail where the hands are placed for popping to the feet. I didn’t put any extra reinforcement in the hand area so that will be the test. Tail has a patch which makes 3 layers of 6oz so that should be more than adequate. The board weighs a rather heavy 8.5 lbs or so (with 2 fins) and I consider the spyder foam (which feels similar in strength to clark) to be overglassed. The stringerless shaped foam prior to glassing weighed 3.4 lbs. I’ve set the twin fins 10 3/4 from the tail which used to be my standard twin fin measurement, but this board is a little longer than the ones I built in my younger days. Its also got a rounded pintail (although I have built a couple of round tail twinnies before). I therefore, if anything expect the fins to be a little too far back. If this is the case then I’m hoping that by moving some of the load onto some front twinzers I can balance it out. However if the twin fin placement feels just right then I can grind down the front twinzers into superchargers. Thats the theory anyway - I hope to find out very soon. PS. hats off to the styro/polyester builder for making his methods open source, his 3 stage suncure method may be a good way for a first time laminator, but $35 no way. I just blew almost one third of that budget yesterday on disposable vinyl gloves, 3 sheets of sandpaper and a small can of paint!
Go ride 'em and report Mr. J. And congrats on getting it done in you apt too. Just proves that all my years of bitching that I had no place to try shaping were bunk. I am surely spoiled with the shed by comparison. The weight sounds OK to me - considering all the boxes you were installing and the foam itself. Wishing you a week of consistent surf for testing out the shape & fin configs. Eric
I was at home depot the other day and didn’t see the pink or blue foam. They had white foam for garage doors, I don’t think it’s the same thing. I’ll have to check lowes.
yep victor - all the HD’s around me seem to stock different insulation foams too. If I do this again I’ll drive to the ‘other’ HD - They have blue… beats having to paint the pink. good luck at Lowes
Hello ‘victor, I couldn’t find xps (blue or pink) in hardware stores, it seems that in the dry climate of Cali they are not too bothered by the water absorbtion problems of white eps and only stock this. I would never build with eps again (I posted why some time ago) - unless I wanted to get into vacuum bagging divinicel sandwiches. Hello Eric, I figured if I could build a nitrate and butyrate doped model aircraft and airbrush it against a backdrop of poly-tarps then indoor surfboard building would be feasible. It was worth the inconvenience although I don’t think I’ll do it again, but definately will build again in a more forgiving enironment. Testing began today. Early morning San Francisco beachbreak. The gulf of Alaska semi windswell now replaced by waist high+ NW groundswell. Well thats what the report says. To be honest all groundswell whether it be from the South, North or West looks the same to me - it was coming in longer lines anyway. Surface was moderately textured but not choppy. Although I’m aiming to tune the fins into some sort of quad, the first session was ran normally aspirated with just 2 Future twin fins.Paddling out I believed I had obtained the use of all that area in the 16" nose with the low entry rocker. When under my arm the board looks noticeably less rockered than any of my other shortboards. Its easy to get an over enthusiastic impression with a brand new board, however this board does paddle well for a 6’ 6" - with 3" of thickness it ought to. I’m a lightweight and it severely tests my ability to duckdive. I can do it by tipping the board on edge during the start of the dive - even my 6’ 9" hybrid doesn’t need this technique and can be dived more easily - its nose is 13.5" by comparison. By only installing 2 fins I’m able to establish its natural twin fin behaviour. Despite what I said yesterday the fin position seems about right - but quite likely my riding preferences have changed anyway since I last used twins. I no longer feel the desire to pack as many turns as I can into a wave. I don’t feel the need to move them more forward and it displays the normal tendency to slide when turned flat. Due to its extreme 21 3/4" width and flattish rocker it can’t be pushed hard into turns. Instead it prefers to be cruised, but in a responsive manner due to just 2 fins. Getting the board to trim is the enjoyable part and on one of the larger waves I notice that the fastest trim line takes it to the bottom of the wave quickly, but a bottom turn soon sends it back up… After 3/4 of an hour or so of this, I interrupt the session and install Future longboard side fins in the front boxes to make it a twinzer. Although sliding boxes would be allow testing of different positions the futures do have the advantage of requiring minimimum pitstop time - the screws can be left in the boxes and plonking in a fin takes a very short time. The first wave gives impression that it is slower in twinzer configuration. I suppose there is too much fin area now. It also blows my theory that the rear fins would need to be moved back. The twinzer is stiffer and moving the cluster back would needlessly stiffen it more. It does feel more like a thruster and has lost its tendency to slide. Although it will hold a higher trim line which allows it to stay in the steep part of the wave for longer I believe it to be slower overall. Cutting back is harder too. A half hour of this was all I had time for. Can someone tell me what “tracking” is exactly? Is it just directionally stiffening up a board or is it sort of uncontrollable locking of a board into a straight line? My board does the former but not the latter in twinzer form. Conclusion is that it works better as a standard twinnie, reducing fin area or supercharging seems to be my best options for running it as a quad. I’ve got something meaningful to do in work now so won’t get the chance to test it for another couple of days, but already I consider this board to be a success 
Sounds good Mr.J - I think it’s hard to beat the loose feeling and speed of a twin. Maybe an idea would be using the regular twin side fins and a small trailer. Less fin than a thruster yet not quite as slidey… Sounds like you’re probably considering that, and a few other options, already. Tracking - in my understanding - is the tendency for a board to stick on a certain line. example - on a tri, too much fin with not enough cant or tow would tend to make a board track straight. Outer fins with Tow and cant make a board, to me at least, kind of static & directionless going straight, but lively(er) in turns - the outer fins are set up to flow better through the water when the board is on edge. I had an old G&S tri-fin from the beginning of the tri-fin era. it had big fins set dead straight in boxes . The board flew going straight. to turn it was an athletic event in itself. stand on the inner rail and push hard with the back foot, then you are speeding up the wave and had very little chance to turn it back down. I gave that board away and bought a Caster - probably the best board I ever had. Anyway - hope that helps with tracking. Eric J
I’ve been lurking on this thread wondering what the heck was going to happen and all I can say is Bravo! In spite of all the hassle, you managed to pull it off and are now in the fine tuning stages of fin specifics. Guys like you, Crabie over in Hong Kong and the guy who has posted the 35 dollar board stuff are the real innovators… I feel like I’m painting by numbers in comparison.
Last night I had about an hour to play on the Pink xps blank - snapped lines for the carbon-fiber deck/inlay thing on top, and the fin boxes on bottom. Routed the main FU box cavity. Future boxes and CF inlay strip routed next. Need to set the boxes and color the blank. and so on. I hope to get some time this weekend to work - getting close enough to taste it -and Mr. J is already in the water…! Greg L. if you’re reading - I hope you got my email (?). If I can I’ll call RR today to confirm. John M. - No way is what you are doing by the numbers… maybe this is just a bit more free-form. While it’s fun to mow foam, I’m not sure I want to have to mow quite this much anytime soon again! It’s all over the yard and under the bushes - since my kids were making pink foam patties mixing the dust with water from the kiddy pool. Hopefully the neighbors won’t complain…much. thanks, Eric J
thanks for the encouragement John, I genuinely appreciate it. you have experienced tracking first hand Eric so I think your description must be correct. In that case I can say that none of my boards have tracked. My thrusters have had proper toe in and when I tried just slight toe in on a twin fin it was on the Mark Richards/Martin Potter influenced twinnies which had fins set a decent way up from the narrowish tail - those things are so loose that I couldn’t imagine them tracking. Could you explain how you snapped lines for the carbon stringer inlay? The method I used for establishing a center line on my stringerless blank wasn’t very good.
Test Session 2 took place early this morning. Same location - SF beachbreak. Similar size waves - waist high+ with a light cross onshore wind. But the gulf of Alaska windswell is back! There is also a slight drizzle from the grey sky. Not enough to put out the beach fire smouldering on the sand. Why oh why do ppl light these things and smoke out the car park? I suppose the homeless ppl need to stay warm, this is an urban setting in America after all. No sight of the lady who pushes her supermarket trolley collecting plastic bottles. A man is rummaging in the garbage bin in front of me. But at least I feel safe, unlike some of the weekend dawn patrols I have experienced in Australia - its rather unnerving to arrive at dawn at a certain rural australian beach and find the semi conscious participants of a drunken binge - beer bottles all over the carpark and on the roofs of their souped up V8s… The groundswell present at my session 2 days ago has gone and so has the TV camera crew that were a few hundred yards down the road. I found out only yesterday that they had not come to record the momentous maiden voyage of my blue XPS project, but to cover the story of the beached whale covered in bites. When I asked if it was safe to surf there on another online forum yesterday evening I was ridiculed. So here I am, the whale has now been buried above the shoreline. The oils reported to be running from it yesterday probably seeping into the sea attracting predators from as far away as the Farallon Islands. I put on my wetsuit and prepare myself for entering a seething frenzy of great white sharks. Fortunately a boogie boarder turns up and says he is going in too - just one other really lightens the atmosphere. Anyway I’m here to have fun not destabilize my mental health so the board is in pure twinnie form again - I want to re-aquaint myself to the twin fin feel for objective comparisions with the next configuration. Despite being reported as windswell the waves still pack a punch and are breaking fairly close to the shore. With the waves more closely spaced than last time I’m struggling to get my duckdives right - the tipping the board on edge method of diving the nose is not easy. The fast waves didn’t leave room for cutbacks and I’m not sliding on my 2 fins. The most memorable wave has me performing an angled takeoff on a steep section and I achieved a feeling of effortlessly flying along it. After 3/4 of an hour or so its time for a fin change pitstop. In go the front longboard side fins to make a twinzer, I dismantle the rear of my tri fin which was in the car and swap the 2 big twin fins for the side tri fins. I now have a reduced fin area twinzer compared to last time. Last time’s setup had the base of the front twinzers exactly mid-way on the leading edge of the future twin fins - intentionally built like this to match specifications dredged up from the Swaylock archives. But this time the front fins sit with their base relatively further forward of the leading edge of the smaller rear fins - now the overlap between front and rear is just 3/4", last time it was 1 1/2", this was not planned and just the way it works out with the shorter base from the tri fin Future template. The trailing edge to tail distance of the rear fins remains the same (10 3/4"). This is a big improvement on last times twinzer, the drag of all that fin area from the previous setup has gone. The board has noticeably more drive if pushed into its turns than the pure twinnie too. The tide had moved making the waves harder to find and I only had time for 3 waves. I noticed that my rear foot seemed to be quite forward on the board compared to where I rode it as a pure twin. Maybe my theory that twinzers can have their whole cluster moved further back is true in the situation where the fins are more evenly matched in size. Despite what I felt about the drive I believe I had lost the ability to get that effortless flying feeling. In other words the board was more suited to being driven into turns than being cruised. 3 waves isn’t really enough and before I get the dremel tool out and start hacking the front LB fins into superchargers I really should give it more testing in its present configuration. Not sure when that will be - can’t surf tomorrow and hoping to unleash some of my point break tri-fin weaponry on the weekend. At the moment I would say the pure twinnie is winning, although the reduced area twinzer is more drivey like a thruster. This board is intended to provide an alternative to my short tri-fin for tinkering with junky waves. For when i feel like a change. The flat rockered blobby outline is not good at vertical manouvres with either twin or twinzer, so if I’m in the mood for vertical turns then I should be on a thruster anyway. For what this board was built for, the cruisey speed of the pure twinnie puts it in its prime. to be continued… - the supercharged twin and 2+trailer.
how is the foam working out? lots of flex without the stringer? Denting?
Mr J - Re the Snapped lines - I can’t say this method was really good either but I needed something to work off of. I used a chalk line before templating too, to get a center line on to the blank to measure from - of course a chalk line is easily wiped/sanded away so after the initial measurements and cut out of the outline, everything was done freeform/visually. I used a Regular old construction chalk-line (string impregnated with colored chalk on a reel - available at any Home Depot) run from the nose point to the visual, not measured, center of the rounded pin tail. (The more I tried to measure, the more I got frustrated, since without a stringer for reference it’s almost impossible to keep things square -I’m sure you realize this) the Chalk line - on the bottom needed to be held up in the middle (because of rocker) while being stretched taut. and then snapped - worked fairly clean - a little muddy in the tail - once I had the long fin-box situated, the side boxes were measured off of that. - On the deck getting the line was harder - string stretched from nose to visual center of the tail. Becasue of the rocker - I had to carefully pin down the center with my finger and snap 2x, fore and aft of the center, to get the line. I think I got lucky in that it came out straight. I taped off 1/2 inch from each side of the line and routed a 1/16+ x 1" strip down the center to accept the CF strip to lie in (I’m hoping that the CF strip adds some strength and stiffness to the board - the blank itself is quite flexy). I hope that helps. What do you (or anyone) think of the CF strip idea? I’ve never used the stuff before but I keep hearing that it is very strong and stiff. If it adds a bit more stiffness to this blank I think that will be a plus. The strip will be set flat to the deck in a slot w/epoxy and the lam will go over the top of that. It’s just a 1" wide uni-directional strip. To Victor P. - I think this foam has merit - It has some strength, flex and memory, unlike stiffer pu foam though it’s hard to shape conventionally. I think a CNC router setup would cut it fine. Then it would require some more sanding than a pu blank. It’s apparently not the best stuff for production though - we’ve heard here that foam created in the EDRO machines is better. Mr.J can tell you if he has any denting problems in the glassed board - my blank of the pink stuff seems much tougher than a typical pu blank - much harder to dent. Best, Eric