How are the bigger glassing shops handling their fin box installs into eps foam. I am having gas issues, blowing bubbles around finboxes and lifting the lamination. I open it back up and does the same thing with the fillcoat. Adds an extra step I’d like to cut out if possible. How do you deal with this issue?
pico
tell us about the way you do things
like,
where do you route the holes, in the glassing room?
if not, what temp is the room you route in?
and the glassing room, what temp is it?
that should already help a bit!?
wouter
Resin Reserch Quik Kick
What finboxes are you using?
~Brian
install and glassing done in a semi shared space, no temp difference. it is usually fairly cool in the space my guess would be mid to low 70’s. The boxes are the standard future boxes. (not the newer ones with more holes around the box) Boxes are routed and put in then glassing is done when off. I know if more care and time is taken in the install process (i.e. make sure there is plenty of resin around entire box without air pockets )this won’t be as much of a problem but in a higher pace shop how is this avoided?
Pics may help - I’ve not had issues of note, but I’m kinda sloppy, and not so concerned with looks. Never had lam lift…???
I don’t have any pics , but I’m suprised no one else has experienced this. I’ve just been sitting over the board watching it gas and create an air pocket, then start lifting the glass right off the board. I push it back down get some more resin on it, attempt to push the stuff into the pocket and moments later it does it again. Half hour minimum wasted nursing the job.
Obviously the blank is gassing due to a temp change. The shop is not insulated well, so every night the blanks probaly get cold and spend the day warming up.
I’ve thought maybe if I do a reverse layup, then route for leash cup, flip and lam bottom the gas can escape through the routed hole easier than through the resin, and cloth. Glass shop laminators where you @?
I’ve seen a couple of EPS boards do this, particularly on hot days and often near the stringer… there are probably better solutions/suggestions out there, but a) try an icepack on the board, as chilling it down can reduce off-gassing, b) and yes, if you’re adding a leash plug, try drilling the hole for that, and leaving it open while you are doing the fin boxes… pressure can escape there. Oh yeah, c) if possible try doing the work later in the day when ambient temps are falling.
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I know if more care and time is taken in the install process (i.e. make sure there is plenty of resin around entire box without air pockets )this won't be as much of a problem but in a higher pace shop how is this avoided?
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You answered your own question. Use plenty of resin, enough so that it squeezes out a little when you install the fin box and lightly wipe off the excess. That's how you should do it and how you would do it in a production setting where you don't have time to babysit an air pocket in your glass job. If it happens again, take a pic of some sort and open the weave where the bubble starts to form to allow the air to escape. You may need to watch it a bit to make sure you've opened enough, but that usually works.
ok thank you gentleman. installs are done before boards are passed to me . I’ll request cleaner and complete installs, or take the time to fill some resin under box.
For 10" center boxes, I use a smaller gap template for eps (about 1/32" clearance). This minimizes the amount of epoxy and heating. Level the board, line the hole with 4 oz and spread the epoxy all around, use enough resin to fill 3/4 up the sides with the box in. Put in the box with your upright tool and align. Once this is semi-hard and the heating stops, fill with another epoxy/micro-balloon/Q-cell mix past level. The thicker mix will allow overfill without it running everywhere. Using 2 fills like this keeps bubbles to a minimum, but you still have to babysit the last fill. Obviously, the fastest setting epoxy is best for this. On flanged fin boxes you have to do it in a single fill, so use enough resin so that you have some excess come out after the box is installed. I normally set all boxes/leash plugs/vent inserts when I’m sealing the blank with the same epoxy/micro-balloon/Q-cell mix.
There’s a lot of production shops that don’t really install boxes right; if it looks OK from the outside that’s good enough for them. Many use the same 10" router templates as for poly and the gap is too big. Once the fin hits a rock and the whole box comes out with the fin, the melted foam story is apparent. I’ve seen lots of these this past summer. For production with epoxy/eps, it’s all about sequencing so that you do the same thing on all the boards at once rather than one at a time. The shops that don’t get this are usually the ones with consistency problems, not just on finboxes.
There are other ways to put in boxes using foaming poly adhesives and the like, but you still have to epoxy fill over them and then there’s more problems with bubbles than if you just set them using 2 fills.
Yep, 2 fills and slow kick. Tighter route out for the box and when I do the first pour I baste the sides of the routed out cavity with resin to “seal” it. Takes twice as long but the boxes are strong for sure. I line it all up tape it down so it won’t float…let the first batch kick and then top it off.
is the board glassed on the deck side? before you are glassing the bottom? you may need some vent holes so the board can gass elswhere.
like the leash cup or vent plug, this is one of the reason why I use vent plugs in my eps boards
I glass the bottom first then drill a small holes one on each side of the stringer where fins will go
then glass the deck. the vent holes will let out gass's so the deck lam wont volcano.
then fill coat the deck and drill and install the vent plug complete with the inside drilled to the foam, you could do the leash cup also
now the board is vented for final bottom work
route out the box's, set them with slurry, do a clean job
then football patch over them and hot coat
no problems,,,,ever!
That Resin-X stuff (urethane resin) kicks off quickly with little if any exotherm.
also ,,,I was thinking,,,
you may want to open the weave in the glass around the boxs to let out the air
thanks ken and john,
Yes I open the weave and let air out once it starts bubbling. I have been doing all reverse lay ups lately, so I can route the leash cup after the deck is off, flip and lam the bottom. This was the next thing to try and you have confirmed it should work. Appreciate the insight!
Of course after this thread I’m also gonna mention to the installer to top off the boxes upon install, and that should save a lot of weave opening later. Thanks again.