I still can't understand how to shape the foil from flat foam, sheets or block. I can't imagine shaping it with a planer. That would take forever and be really inaccurate. I am picturing the hotwire work though. maybe glue in a stringer and drag the hotwire along it? As long as the stringer won't melt, it would be pretty easy.
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Using a planer is not as accurate, but it isn't so bad. XPS custs like butter. I shaped the nose rocker into the XPS alaia that I made from a 3" block. That part of the shaping exercise took no more than five or ten minutes.
I'm no pro, but here's what I did:
- I initially put the depth of cut at zero
- I then placed the planer on the bottom of the board, in the center, and facing forward. The blade was at the point where I wanted to start the curve.
- Moving toward the nose I slowly increased the depth of cut.
- Repeat the same cut to the right and left of the little trench in the center
- Go back to the center and start over.
I actually wasn't as methodical as it sounds. I just did a lot of back and forth movements twisting the knob so the depth of cut was zero on the backswing. I faired the curve by sanding it with a two foot wide piece of plywood that had a couple of sheets of sandpaper spray glued onto it. It helps if you draw the rocker curve on both sides of the blank, so you can check to see if your cuts are accuracte. You can do this by taking regular measuements, adding dots with a sharpie, and then connecting the dots.
You should stop a little bit above the line, and use the sanding block to get it perfect.
Note: I cut the rocker into the board after I cut out the outline. There is a lot less foam to remove that way.
This method worked for me once, but I'll probaly buy a variac, and put together a hotwire harp someday.
I cut rockers and profiles out of EPS and XPS with a planer. It takes time, but it’s not a problem. Just need to have a way of measuring the curve. Do the bottom first then profile the top. You can go fast at the beginning, but go slow when you get close to the curve you want or the foam will tear.
I only have a few rocker profile jigs, so I start by hot wiring a basic curve in the foam, but I always end up changing the rocker to something different. I give myself at least 3 inches of thickness to make sure I can do whatever I feel like.
I cut rocker slices from 6" wide blocks, so I get a piece 6" wide and about 3" thick. Then I either glue in a pre-shaped stringer (has profile of middle of board) or glue up several pieces to get the width I want. If I use a preshaped stringer, I’ll start with the middle, then cut the foam to meet the stringer before adding the sides. Then I just cut the sides down to meet the middle. If I don’t have a pre-shaped stringer, I draw the rocker on the outside edge of the foam and start cutting it down. Just make sure you true up the bottom of the blank before working on the top.
Hot wiring the foam would be faster and cleaner, but I haven’t had much luck with cutting the whole width. I kept getting about half way in and the wire would break leaving me with a wire stuck in the foam. Slices I cut are not perfect, but I fix it with the planer and sanding blocks once I start shaping. I have new thicker nichrome wire, so that may change it all.
Here’s a photo that shows a blank being built. This blank had 2 - 2" wide balsa stringers. I glued them to the middle piece of foam making sure they were lined up properly, then I cut the foam down before gluing on the sides. Once the whole blank was glued up, I went to town with hand saws, my planer and an assortment of sanding blocks. I get the bottom to where I want it, then work the top down to a flat blank. Then I cut out the outline and finish profiling the top and rails.
This is true hacker style board making. Not fast or easy, but I don’t care.
Are you doing vertical strips like TaylorO? Looks like you are starting with 6" x 6" strips of desired length, then giving them rocker and adjusting thickness accordingly.
If you don’t mind my asking, where are you getting your balsa stringers?
I know you didn’t ask, but I use 9/8" clear cedar. I draw out the rocker and foil, cut and sand, then split w/band saw, then smooth with joiner (I’m lucky to have access to a fairly decent wood shop.). Then I drill holes about every 18" and screw it into the foam and cut with hot wire. I’m forever grateful to Ambrose and Topper for letting me hang out and watch how it all goes down.
I do more like what one guy said than Sharkco. I cut out a rough outline first so I’m not mowing foam I don’t need to. Then flat the bottom, get the deck close to what I want, tighten up outline, bottom contours, deck tight, put rails in.
I laminate 4’ or 3’ pieces from national balsa or lonestar balsa. I bought a bunch of balsa couple of years ago, everything from short thin pieces up to 4’ x 4" x 3/4" from a widow whos husband built model airplanes.
I also also bought 3/4" x 4’ x 3" pieces from lonestar after they had a terrible fire. I glue 4 pieces together to get the length I need staggering the joints and adding a slight bend to get the rocker I want. Then I cut out the rocker with the profile. If need more than the board can give me (like if I use 3" wide wood) I do a scarf joint in the nose to get more wood up there. It’s really easy to laminate several pieces of shorter wood to get a longer piece. It’s also easier to cut the rocker and profile when it’s a thin piece of wood. You just have to be pretty sure of what you want. I often change things mid way through, so it’s not like you can’t make changes.
I tried making a board without cutting the profile and killed my planer, so I always cut the rocker and profile these days.
I also drilled holes through the middle section of the blanks with extra wide double stringers. If you look closely, you can see holes in the stringer. I do that after the middle section is glued up. Sometimes I’ll use thinner pieces like 1/4", but the foam I got was 6" thick, so I made several stringers that were up to 2" wide. Some were only 1 1/2". I wanted to make the boards 20 - 21 1/2" wide.
I got 3 blocks of EPS from a contractor for $20 a piece. They were 6" thick, 4 feet wide and between 6’7" and 8’ long. I hot wire a rocker that is about 3 1/2" and I only do the bottom, so I have a lot of options for what I want the end product to be. I cut up 2 blocks with one set being over 4" thick in case I want to make a SUP. I also got 2 blocks of XPS foam 4" x 2’ x 8’. I hotwired a whole board out of one block, and cut the second block into rocker strips. I can make much more with the rocker strips.
The beauty of this method is that it’s cheap. My blanks are about $5 a piece. The local EPS manufacturer wasts over $500 for a 8’ x 48" x 28" block.
If I was doing this regularly, I’d look for 10" to 12" wide blocks then there’s just the middle seam, or you can do a 2 stringer.
Going with a commercially produced blank is the easiest and fastest way, but this process is great for learning how to use your tools. Nothing like taking a messed up piece of whatever and making it into a decent surfboard. The other thing is that you can make your board thick or thin, and you can do all kinds of wild bottoms or tops. Your not limited by a close tolerance blank. And you don’t have to put a stringer in. I do more of these boards without wood stringers. I take some of the XPS and put it between the EPS and I get 2 narrow bands of blue with 3 wider bands of white. The last board was 3 EPS with XPS on the outside just where I needed to get a little extra width.
What about the sufersteve.com method? Draw rocker profiles on each side of a block of XPS (blue dock block) and just start removing foam with a drill sander. Seems like a very inaccurate method. But then again, so is using a planer for the same purpose. On-the-fly depth changes are still prone to devastating error. Then again, I shaped a board before with nothing but a sur-form.
Hi there, it has been a few weeks since you first posted this. Has your glued in rocker flattened out yet? I mean, are you still gazing upon your unfoiled blank and wondering what to do next? There are looks like a few of many ways to go about it that people have shared with you. If you are trying out the not buying a blank route you have to chose one of these methods or figure out your own way. I am writing to a virtual personality that could be one of the selected individuals for whom surfer steve has a kindly message urging them not to try. I found his site before this one and it was my guide for my first board. It was a great intro but i dont recall much on foiling and that board was heavy and sluggish. Using a drill sander on foam sounds like a beaver on acid. Planers can be very accurate. i just started using one on my last couple boards, now im going by ticks and shadows with double checking band widths instead of drawing lines all over the place. its not modified either, just a plain old makita, and even that is a big improve
ent in results over just a surform and sandpaper. All i can say is pick a method and try out some tools, if its not for you, buy another blank? A chaisaw could have devastating results, but a planer set on low depth cut, well youd really have to put some effort into devastating your board. Foil the damn thing so surfding can answer your XPS glassing questions!
Well to “foil” a board which is already rockered will cause the rocker to increase. Not something I want to do. I want to create a foiled blank with rocker in it. That was the original inquiry of this topic. So I guess the only way is to hot wire it, or try to shape the rocker in by hand with a planer or sander.
Here try this, i posted a thread called ’ string age hotwiring tip’ last week. The instructions are easy and the material list doesnt take long to gather. After that you will be headed in the right direction and you will have a new appreciation for power tools. Good luck and have fun!
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Planers can be very accurate. i just started using one on my last couple boards, now im going by ticks and shadows with double checking band widths instead of drawing lines all over the place. its not modified either, just a plain old makita, and even that is a big improve ent in results over just a surform and sandpaper.
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Good for you! It's always amazing to me that the people who say planers are ''too hard'' haven't actually used one for more than 5 minutes.
To the OP, you can foil from the deck and not mess with bottom rocker, or foil from bottom and not mess with deck rocker (if you've made yourself a blank with no foil). Or you can just hotwire the foil/rocker you want, which makes a lot more sense. There are about 4000 ways to low-budget hotwire on this site. And one ''hotstring'' method, thanks to dpicton.
I’ve busted out the planer, and after tracing rocker profiles on each side of my block of foam, I started shaving down the bottom of the block with the planer.
I’m going rail to rail and overlapping most passes. Started in the center of the blank and moved my way to the nose first and then center to tail, rail to rail passes with the planer. It is taking forever, but I’m almost done.
Once I finish the bottom side (easy part), I’ll have to figure something out for the deck. Around the nose is going to be difficult to cut out.
When I finish the rail to rail passes, I’ll begin the standard blank-skinning routine to smooth the whole thing out. Tail to nose on the underside. Rails will be no sweat. Planers love XPS.
He said he doesnt know if hotwiring is feasible, so he probably just doesnt have one set up yet but i agree its definitely worth it…faster, less mess. What i wanna know is where is surfding’s xps sandwich build thread that he said he was gonna do…did i miss that one or does he just not wanna get poked in the eye? I would find it interesting…this one turned out to be a how to make your own blank/intro to foiling thread with a misleading title
What i wanna know is where is surfding’s xps sandwich build thread that
he said he was gonna do…did i miss that one or does he just not wanna
get poked in the eye? I would find it interesting…this one turned out
to be a how to make your own blank/intro to foiling thread with a
misleading title
