Sanded too deep on stringer - how to reinforce

I put a pretty deep foil in the tail of my board, and when the final coat was sanded, it went a little too deep around the stringer above the fin box.  So deep in fact, that I can see the fiber glass weave and it’s very soft.  Is this something I could pour another sanding coat on, and sand it down?  Or should I lay more fiber glass over it too?  It’s on the bottom, so I’m not putting my foot on it (knock on wood).

It’s an EPS blank with Epoxy resin.

 “I’d never in a million years hand off a shitty job and say “wellp, sorry, I did my best with the hand I was dealt”.  But, that’s just me…”  That’s what you did, even though it was in ignorance.  Good luck on your next board, and try not to drop the f-bombs so cavalierly.  Your still blaming everyone else for your improperly designed and finished shape.  In an age where cnc’s jam out boards, well shaped and designed boards still have credence, but sadly the shaper’s role has been marginalized; while neophytes parade as master craftsmen.

I say things sometimes just for educational value, and of course to promote a healthy discussion, and perhaps in the process we all learn something.  Taking the board back into the shaping room and showing the guy how to take down the stringer is great if you have the time, or the laminator with a pad and a block plane is pretty standard also.  Yes, the sander should have caught it, but he should have been made aware, and because of the extra challenge and work paid more for the task.  Sanders reshape boards with power tools, and the hard pad takes it to the high spots.  A well shaped and designed board will make the sander’s life easier.

 I will defend the craftsman, such as the sander, for the gremmie’s mistake, and by the looks of the picture, there probably was bits of beads still floating and not finished cleanly, so the lam had to be “floated” in the first place.  The sander didn’t sand through, he just brought up the weave.  As I have said before, making surfboards can be a comedy of errors, especially when the actors don’t know their roles or perform poorly.

hey blake

you can do both options

one is just more work than the other

do you know why you sanded through in that specific place?

if it is around fin boxes, add fibre, sand edges a bit, hotcoat, sand down.


The stringer is a lot higher in that area, because of the deep concaves on each side.  So chances are, it was a quick and sloppy sand job.

I didn’t do the sanding, since I didn’t do the glassing either.  I had a shop do it, and the sander must have been a little heavy handed.  Usually I’d bring it back and say “fix it!”, but I don’t feel like waiting a week for him to fix it.  I’d rather just do it myself tonight and surf it in the morning.

I’m learning that if you want something done right, you gotta do it yourself.  I’m the same with with my bicycles.

hey blake

in a shop, they expect the board ready to be sanded

if you left the stringer too high for whatever reason, it gets sanded down.

you would sand it down too if you had a high rpm sander

but, use fibreglass, 2 layers, one sacrificial layer

large area! the area around the spot is prolly weak too. i had that happen a few boards when i just started shaping.

do you have a picture of the board?

we need more board porn here


Here’s the board…

When you say “ready to be sanded” what do you mean? All contours of the board were intentional, so what should I have done to get it more “ready”? The stringer sticks up there because of the way I shaped it. So if I was sanding it I would have taken a little more care around that area. I understand hitting high spots along the rails or deck due to the my incompetence, but I feel like the affected area should have been treated a little more carefully.

Maybe I’m wrong.

Mr. 1st shape calling BS on the sander when the board was not properly finished on the stringer.  You asked for opinions, and this is the truth, but you probably can’t handle the truth.  Your finish work sucks, as i can ascertain from the picture, and the best you can do is blame someone else.  I hated sanding boards for idiots who thought they could shape, but couldn’t.  “The sander doesn’t lie”, my friend Dane New used to always say.


I’m not calling anyone out, nor am I placing blame.  I’m simply asking how I can fix it, and avoid the situation in the future.

Not sure why you’re so bitter, but thanks for your help.

Start by taking down the stringer so it doesn’t read high for the hard pad, on the next board.

clik on the clip on the bottom left

and dig how tripped out these guys

are on hood ornaments and tail lights

you think surfers are touched by the 

ficle finger…

dig the other world,these guys

could probly get to name calling about 

stainless steel screws vs. monel.


Let me start by saying that I agree with most of what the Rat says here and I have learned loads from his brutally honest commentary and advise.

This is different.

Certainly not a professional sander, shaper, glasser etc. etc. But I am a businessman…and a very good one according to the IRS.

If somone was paying me to sand their board…then my job is to sand the board without screwing it up. If the board wasn’t properly shaped or glassed then wouldn’t I have a duty to inform the customer of the problem…instead of; “well shit stick can’t shape so I’ll just fuck this thing up for him!”

That’s a fucked up attitude! If you don’t want the work then don’t take the job! If you take the job do it right!


Handle that fucking truth!


Wow ok I understand your fin box issue. Its 50% your fault and 50% of the glassers. Had you asked me to glass your board and you handed me that. I would have said “No Way Jose”  as I see it as it is. Then I would have pulled ya in the shaping room and show ya why. Then I would have showed you how to make it glassing friendly and why. Then charged ya more for your glass job. Maybe give ya a deal on the next one if ya learned something worth giving ya pro deal. 

Now that I got that off my chest. 

Fix that box with 2 layers of 4 oz. Tear drop patch over the box caping it. You need to beef up the front of that box and the area around the box at least 2" up and around the edge of box. When ya cap the box scratch it up good. 40 grit and sand around the box edge so ya make a good solid bond. Then take your time and sand it. I don’t want ya sanding the area at the point where the box meets the Keel because that is not Vee thats a boat keel. I can see that in your pics half blind and 5 beers. 

Tip on the stringer issue. Stick with Vee and master the basics before getting all fancy.  It would work better then that High Stringer wood running up under your feet. You run a Keel Vee that far up to your front foot it will hang ya up from making smooth rail to rail transition. That Keel would tend to make the board tracky. Everything works that would only make it more work?  

Never blame the other guy if you’re the guy!

Just saying Kiss 

Great solution.  Very fair.  

Thanks for all the solid advice.  Next board I’ll be doing all the work (shaping/glassing/sanding/surfing), so I’ll know first hand what problems I’ve created.  I never expected the glasser or sander to fix my fuck ups, but if I’m paid to do a job, I damn well do the job.  I’d never in a million years hand off a shitty job and say “wellp, sorry, I did my best with the hand I was dealt”.  But, that’s just me.  And in my line of work, I’d never work again.

That said, I had no intentions of making a safe board.  I could have made a flat to vee bottomed, clean railed, square tailed board.  But I wouldn’t wanna ride it.  I wanted to make something silly and fun.  Who cares if it’s my first board.  I wanted to carve it all into one piece of foam.  At this point, I’ve been surfing long enough to go down the line on a fucking door if I had to.  So why not start off experimenting?  I have no intentions of shaping for a living, or for anybody else.  So if the board rides like shit, it’s all for my own entertainment.

I’ve ridden the board a few times, and it rides exactly how I expected it to.  Completely stupid.  And I love it.  The next board will probably more conservative.  In which case, I’ll be using all the amazing info I’m learning from this forum.  So thank you all for that.

I’m gonna try a coat of Epoxy on it tonight.  Mainly to keep it water tight.  If the whole box rips out one day, no big deal.  I shaped this board for one thing only, to get my hands dirty and start breathing foam.

SANO I do the same thing when that happens. If I have a free room ill point out what needs to be fixed and let them try to fix it. You are only allowed to use these tools, and dont touch anything else. {Either tools or on the board. Usually a spokeshave and some 120 grit do the job,



Im actually suprised MAC put a lam on there. We dont put lams on most backyard boards. No personal offense to backyarders but thats a common policy at glass shops.

Chiron is a good old friend of mine. I shaped it there with him, so he warned me of everything I was getting myself into. Again, why I’m not blaming the shop at all. So I’m sorry if any of you think I’m straight up blaming someone else. 

I hope this doesn’t reflect poorly on MAC, cause they really do stand up (no pun intended) work. 

No not at all. The reference about the lam was just in general. 

If you’re just seeing weave, why not just add some hotcoat? If theres no exposed foam, the lam coat is obviously still in place. Adding some fiber wouldnt hurt it, but why add weight if you don’t have to?

@ Sanolocal, I actually saw something like this at my shaper/boardbuilders the other day. I looked at the board and the glass job was pitiful- exposed weave, cracks, visible patches. However, it had wayyyy too much vee and the rail edges on the tail were kind of a mess. Thing was, the kid had taken it to a very well known, extremely recognizeable glasser. My builder said he would have done the same thing, said ‘fix this or this won’t glass.’ why would you want somebody walking around with a board with a crap glass job saying that you did it, even if it was unavoidable?

I think it is clear by now that you don’t know how to shape. Here is an instructional video that will help you, immensely.