Sorry if I post too many questions yall. I do use the search function often, but if i find it fruitless I will start a new thread
This time I want to ask about flattening rocker. I cannot wrap my head around where precisely I would remove foam in the middle of a blank to create a flatter rocker, and I’ve seen advice against trying that anyway. So I’m resorted to using an oversized blank and shifting the outline template backward to flatten nose rocker, or forward to flatten tail rocker. Adding rocker with a planer is more straight forward.
My question is wouldn’t sliding your template back and forth alter the rocker apex slightly? How are all the other amateurs flattening the bottom curve when needed?
The easiest way to get a flat rocker is to start with a flat rocker. That’s why blank/rocker selection is so critical.
As a backyarder with minimal skills, I will repurpose a blank to a design that better fits it before I’ll try to significantly flatten an existing rocker. Adding more at the ends is easy, but redoing the entire curve is an exercise best left to the pros. I’m foolish, but I’m not that foolish.
Start with the right blank… You can pretty much get any rocker in a blank you want within a week from any of the “Big Four” foam manufacturers. Experienced backyarders and pros will tell you the same thing. Start with the right blank. If you’re going to take a former piece of junk, strip and reshape; go figure it out and then let us know how it flys.
I agree i should have gotten the correct blank but it’s too late now. The rockers aren’t terribly off but im used to adding rocker, not removing it.
so i could shift an outline template back orrrrrr…
ive seen rocker removed by finding the apex of the bottom curve then planing it down and blending it into the given nose and tail rocker. Then you have a bottom curve with a flatter middle/apex. Then you go back snd add rocker where needed to hit your numbers.
im just not confident in my ability to execute that
If you have to do it, this vid shows one way of doing it. While you’re at it, he’s got a bunch of how-to vids so you might want to pick through those. Unlike most of people who are doing shaping how-to vids these days, he not only actually knows that he’s talking about, but he can also surf.
You can make a rocker template and use it to guide you where to take the foam out. A flat rocker measuring stick will do if you have a good eye. It’s also really helpful to use a modified planer and go from zero cut to the cutting depth you want then back to zero. Cut a little, stop and check, cut more, check and keep going until the rocker template fits perfectly. Be sure to know what your thickness limits are too. Jim Phillips would say, make shallow cuts not deep cuts. Easier to remove foam than add foam.
I made a simple rocker jig to make copies of rockers I like, I also have several rocker templates up to 8’ long.
Some people cut out the stringer and replace it with a modified stringer then make the foam match the new rocker when the new stringer is glued in. I had a stringerless PU blank once and it was floppy and easily manipulated.
"ive seen rocker removed by finding the apex of the bottom curve then planing it down and blending it into the given nose and tail rocker. Then you have a bottom curve with a flatter middle/apex. Then you go back snd add rocker where needed to hit your numbers.
im just not confident in my ability to execute that"
Go for it! Check a few measurements in the blank catalogs. Back at the shaping stand use your eyes, your hands and a decent straight edge. If your blank has a stringer, sight down the bottom edge and find your rocker curve. It’s in there someplace - just remove the rest. It’s been said here many times, “It ain’t rocket science.”
Ive got 1/4" of thickness to play with. I made a rocker template last night. I guess im going to try this. Thankfully it’s a board for me and not a buddy.
Going for it…you can see the flat spot coming in. I have about 1/8" of thickness left to use. I have not gotten the nose rocker low enough yet, but im making super shallow cuts to stay on course. So far no disasters.
on the topic of rocker templates: ive made one, now how do i use it? I assume im removing foam where the blank meets the template until the blank uniformly fits into the curve if the rocker template.
