need some help with a fudged Probox install, as the pics will attest these boxes weren’t pushed deep enough into the jigs when installed resulting in too much of the box being sanded down. Nor were the routed holes for the boxes lined with glass as per instructions for an epoxy install on the Probox site.
Initially I lost a fin on my first surf(brand new board), you’ll see on the front right box where the screws have torn out from water pressure from the box being sanded too much. Then after I ordered replacement boxes for the shaper to re-install(properly this time!) I took it for a paddle as a twinny. First wave I’ve laid into a bottom turn and the entire box has ripped out, this is when I discovered he hadn’t lined the routed holes with glass.
Now after having had a good look at the install method recommended by Probox I’m concerned that even if instructions are followed to the letter that I will have problems with losing boxes. I’m a 6ft 240lb kneeboarder, I like fins with a bit of area, the one that took this box out is about the same area as a MR twin but with more rake and is what I use as a standard front fin in a quad set. So what I’m saying is the boxes are going to cop some pressure.
Has anyone else had similar issues surfing fins with lots of area in Probox and are there any other tricks that can be utilised to strengthen the install? And yes I’ve searched through all of the old posts, just wondering if anyone has anything new. The rest of my boards have FCS fusion boxes which allow for a bit of flex and have the hi-d foam that really seems to provide a solid base for the resin to fix to.
I love the idea behind the Probox system but…
How about a hi-d foam or balsa insert in the board for the boxes to be fitted in???
Were the boxes installed into low density EPS? Be this the case you would need some sort of reinforcement (high density foam) around the box no matter what the fin system.
Thanks for the responses fellas and sorry I should have provided more info to start with, board is 2lb EPS compsand construct. Box ripped out due to water pressure from bottom turn, no impact to sand or reef. Just had a look at the foam and it doesn’t seem to have melted around the box.
Obviously all of the boxes need to be routed out and redone, will they require a hi- D insert of some description to be set in or will they hold set straight into the board IF the routed hole is lined with glass?
Which is the stronger method of install?
Bearing in mind that the board is surfed with lots of fin area, usually something like MR Twins as front fins and PC3’s in the back.
I use probox all the time. were these installed in EPS or Poly blank? did they teacup out, or just blow out from a direct hit on rock? Most of the time teacup breakage is from bad foam. Bad foam meaning way too light, or melted foam. I've installed proboxes with great success all the way down to 1.3lb foam.
What need to be done.
1) if the install it too tall. Sand flat to board, take the screws out, put the jig back on the board, and reroute the hole, then reset box....very easy.
2) if using EPs foam, make sure foam didn't melt from therming epoxy. if that happens nothing will structurally hold the box in. To keep epoxy from therming a small ziplock bag of ice on top of the jig and box will slow it down just enough.
3) Routed holes with eps should be slightly smaller, do this by changing out the top bearing on the router bit. smaller like 1/32 or so.
4) glass around the board should be reinforced, meaning you should have 2x6, or 2x4 under the area to be routed. This gives you extra glass when sanding box down around area. Maybe the guty that put the box in sanded all the glass off around the box?
5) don't sand the boxes down too fast. heating up the boxes too fast when sanding will heat up foam...and wierd stuff might happen
6) Put glass inside routed holes and up inside of wall of holes, this will bond into the top layer, foam, etc...and make one hell of a strong build. It also keeps therming down.
All this sounds like a lot of work....but it's reall not. just a few things. Use fiberglass with the install, don't let it heat up to hot, don't sand like crazy person..
Just saw your picture, it looks like your foam melted on the rail side of the hole...the stuff with the blackish hue to it. it looks like the foam beads shrunk up a bit...they look hard and crispy. Not all fluffy and styrofoamish.
Reinstall, and slow down the epoxy in above post....this is especially true now that you have a bigger, and bigger hole to contend with. make sure you put glass in, and butter the sieds of the hole with epoxy for a good bond....cover with a ziplock bag of ice. Put some wax paper down first..then bag-o-ice.
You must be one bad ass surfer, because we push those Proboxes pretty hard around here and the only time I screwed up an install was when I tried out 3M 5200 instead of resin.
We know that the box was installed crappy from the start. 1) if the box is too tall, and you sand it down too much, there is no reinforcement around the screws (which you found out) It wasn't from water pressure, it was over sanded and way too thin to even hold my buddy's 6 year old girls bottom turn. The screws virtually fell out. 2) Then the second install was almost right...but no fiberglass? EPS need some love in the box.....So 3) if we install correctly this time. I would ssume that it will be fine. 2 lb EPS is plenty strong and no need for inserts.
Tell the shaper to slow down and do it right, or you will kick him in his taco.
I’ve done the same with probox and FCS fusions in EPS. Need to have the glass inside the hole. Probox has an installation guide that shows how to install the boxes for EPS foam. If you do it the way they show it is pretty solid. Doing it the right way does not take more than a couple minutes from not adding the glass. 2lb foam won’t need HD inserts. I have been using 2lb construction EPS for a while with probox. Just follow the installation instructions. Make sure your jigs are the right ones too, or you will not get the right depth when you route it out. I have older jigs and they are slightly thicker and have a little different shape than the newer jigs. The other thing is to make sure you push the boxes all the way down. In the past, I’ve added weight over the boxes and only partially filled the holes. Once the resin sets, I’ll finish filling it up. Now that I’ve done it enough, I’m pretty sure that it will come out OK.
The fusion plugs were in very light EPS, had to rip out the Fusion plugs then installed solid blocks. Still haven’t finshed fixing that board. Too bad because I was having a great time up until the fins broke free under the glass. Then the board seemed looser and no drive. Flip it over to check it, then bee-line it to the beach.
Have had thermal issues as well on other extra light EPS boards. Each type of foam will have its own problems.
micko, Sorry you had some hard Luck my friend. Glass is important on any install Foam is the weal link to Probox or any system Glass over usally roll underneath the glass job. Go to www.ProBox-Larryretrofits.blogspot.com you will see I show and explain the glass sock concept that I was taught even as a teenager to do with leash plugs and center boxes. This install concept changed in the early 90’s by glassers to get things done quickly, which is why good ding repair guys make more than glassers!
Here’s a pic of a guy in North Carolina surfing Hurrican 6 t 8ft with 5 fin 7’6" sup board. This guy is 6’4" and his weight is 220. No problem with his board or installs. Feel free to ask any questions my friend My Swaylockian Brothers thanks for stepping in as always you guys ROCK! Mahalo, Larry
