FCS Fins - Repairs

rushy's picture
rushy started the topic in Friday, 21 Dec 2012 at 3:19pm

Recently discovered that I'd mangled the fin plugs and surrounding glass/foam on my PU minimal (FCS plugs with PS5 Core fins). Must have gone too close to the shoreline, but didn't notice it at the time - not until I took the board out of the bag on a trip up the Coast. I'll check before I load up in future.

Anyway, I want to fix it myself so looked up a few websites to get some tips. However, most posts suggested repairs to broken fin tabs still in the plugs, and how to deal with this problem. The posts also mentioned that this is the most likely mishap as the FCS fins are designed to snap off at the tabs, rather than damage the board (which is what happened to mine).

Any experts out there who know some more about this? And any tips for fixing what I have?

poket-roket's picture
poket-roket's picture
poket-roket commented Friday, 21 Dec 2012 at 11:12pm

Rushy,
I've attempted a few repairs to plugs on older boards with varying success, newer boards I've just handed them back to the shapers to ensure a pro finish.

If your plugs are just the two individual circles you shouldn't have too much trouble. If they are these newer one piece fusion type they are a pain in the arse, not being a circle shape.

If the plugs are cracked they are shagged and need to be replaced. If it is an outside fin you will need to make sure the replacement plug has the same amount of cant(angle). If it is just the glass that has craked and not the plug you can get away with reusing it.

I've heard on several occasions from repair shops who completely remove the plug and the foam around the plug and then fill in the entire cavity with foam or qcell, then reglass. They then cut in new holes and glass in the plugs, pretty much as if it is a new board. I've never done it this way myself and have gotten away with just cleaning out the cavity, stripping back the glass about 20 or so mm around the plughole, then dropping the plug back in, screw in the fin to get the plug aligned then reglassing, with a bit of foam dust or qcell in the resin to beef it up.

This video is the best explanation of the repair process I've been able to find

www.youtube.com/watch?v=BLgAVIm4Tvc

rushy's picture
rushy's picture
rushy commented Saturday, 22 Dec 2012 at 8:26am

Thanks roket. I've been considering a few ways of doing the repair, but I agree with you that the video looks like the best technique. He makes it look easy, doesn't he??!!

If it's free, it's for me!

mbuckis's picture
mbuckis's picture
mbuckis commented Saturday, 22 Dec 2012 at 10:12pm

I smashed two plus out on my outside fin and put them back in with q cell about 4 months ago - board still goes ok but the repair is prone to cracking.... If you like the board (or its relatively new) best get a pro to do it bro.... I'm going to have to get a new board soon as a result....

rushy's picture
rushy's picture
rushy commented Saturday, 22 Dec 2012 at 10:28pm

Started the repair today. Already made one error - I cut back the damaged glass too far and there wasn't enough for the fin to rest on when I used it to set the plugs in with q-cell. Didn't realise until I had started to set them back in. Tried to recover, but as a result, the plugs a slightly angled in towards the centre of the board. No much, but enough for me to notice. I'm sure it will surf ok when finished, but as you say @mbuckis, I may still have to get it done by a pro. I'll see how they go.

Anyone confirm that FCS fins are designed to break off at the tabs if impacted?

If it's free, it's for me!

poket-roket's picture
poket-roket's picture
poket-roket commented Sunday, 23 Dec 2012 at 4:31pm

Anyone confirm that FCS fins are designed to break off at the tabs if impacted?

By: "rushy"

Yep thats the idea, they are supposed to snap off to avoid cracking the plugs and glass, although I have difficulty understanding how they are supposed to snap off if you run across something. Side impact yes, but I once ran over the tail of a mates board, the result being the centre fin got pushed backwards in the plugs leaving a gouge through the back of the plugs and into the glass.

Another tip is not to crank up the grub screws too tight - just have them finger tight so you aren't placing excessive pressure through the plug.

For mine, Futures Fins systems look a lot more secure, but I have also heard they don't snap off as easily as the FCS system.

Rushy, don't sweat it if that was your first attempt, I've only done it a coupe of times but found it a good idea to mark the centre line of the fin and mark the plug centres across this line before you clear out the holes and reset the plugs. Also was it both plugs or just one? if one is still intact that should have dictated the position/angle of the plug being repaired. Also I can't remember if its in the vid, but use some masking tape across the tip and down onto the rail to hold the fin in correct position.

mbuckis if your glass is cracking you might be using too much catalyst, this causes the glass to go off too hot and it becomes brittle.

rushy's picture
rushy's picture
rushy commented Sunday, 23 Dec 2012 at 7:49pm

@Roket, I agree about Futures fins being a stronger option. I have a few boards with FCS and some with Futures. I notice you can't get bigger FCS fins than about 5 inches, but Futures go to 10 inches and more. A bigger fin would pop out FCS plugs when placed under pressure.

Made some progress with the repairs today. It might not look 100%, but it will work just fine for me. I've learnt a bit from the excercise so not a bad thing. My next job will be better. As @mbuckis said, I might have an excuse for another new board ;-)

Also, I see the merit in not having the screw done up too tight. Make sense to me.

If it's free, it's for me!

TS's picture
TS's picture
TS commented Monday, 10 Nov 2014 at 10:01am

I'm having a go at replacing one of the FCS centre fin plugs on my board. I am at the stage of cleaning out the existing cavity. On one side of the cavity the hard white material that surrounded the plug is still adhered to the foam. What is the hard white material and what is the best way to clean it out? Also is it necessary to use this material when installing the new plug?

udo's picture
udo's picture
udo commented Monday, 10 Nov 2014 at 10:57am

TS, the hard white material left in the board is what the fin plug is set in......resin with a colour pigment, it does have to be removed ......gently dig it out - trim between the solid resin blob and the board foam with a sharp blade....don't be to concerned if the hole left behind seems a bit large/ non circular....when you refit the new plug the new resin mix will fill any voids......make sure you have the grub screws on the correct side for a centre fin they are offset , the side fin grub screws are not.
lots of vids on utube of fin plug setting and repairing.

rushy's picture
rushy's picture
rushy commented Monday, 10 Nov 2014 at 11:29am

TS, do what udo says.
Couple of things that will also help (ie mistakes I made and learnt from):
- When you mix your resin, add some q-cell / micro balls etc to make it a bit thicker , but not too thick - still able to pour into repair.
- You can add some white pigment (like the pros), but only needed for cosmetic effect.
- As the resin goes off (sets), it gets hot (exothermic). place a wet towel on the underside of the repair to absorb some of the heat. If you don't, it could get a scorch mark on the underside. Glass and foam very thin there.
- Also, as it goes off, you may get bubbles coming out (off gassing from foam). I got heaps. Best to do it in stages, ie fill about 1/3 at a time. Any bubbles can be burst as they appear but you have to do this before the resin kicks. Takes a bit longer this way (filling resin in stages), but you won't end up with resin "honeycomb"
Good luck.

If it's free, it's for me!

udo's picture
udo's picture
udo commented Monday, 10 Nov 2014 at 11:35am

TS, okay to use a bit of talc powder if you don't have any qcell to thicken the mix, I use strands of fiberglass cloth chopped to about 2mm long .
No more than 2% mek hardner in the mix or as rushby said it will get hot.

caml's picture
caml's picture
caml commented Monday, 10 Nov 2014 at 8:52pm

Cant agree with not tightening grub screws up there ppl . If you want your surfing to be fast you need the wheels on securely

eat-your-vegies's picture
eat-your-vegies's picture
eat-your-vegies commented Tuesday, 11 Nov 2014 at 7:22am

caml
i think he means to not 'over' tighten the grub screws. they just need to be firm to slightly over firm but not driven in with a torque wrench lol.
this has allways been an issue with fcs round plugs.
that continuous over pressure often splits the plugs longitudinally.
that got alot worse when fcs changed their plugs to that hard acrylic . a ding repairers dream it was.
these days too, since every one, just about,rides solid glass fins that have no give like the old composite plastic ones , its important not to over tighten the grub screws.
mate, im just yakin about the old round plugs and not the new semi box ones they do now.
ive been out of the industry for a couple of years now and not had any thing to do with them.

caml's picture
caml's picture
caml commented Tuesday, 11 Nov 2014 at 12:55pm

Ah correction there eyv , solid glass fins are almost exstinct . By far most common is resin transfer or semi plastic . Resin transfer are the honeycomb / carbon . But you mean the part of the tab where the grub screw fits is not soft plastic. I tighten my screws as tight as possible without stripping the thread . Often doing it for others whos fins are half hanging out of the plugs , unaware of this maintenance thats needed to keep up. The more movement there is means power transfer doesnt occur and also delayed reactions . If you have a loose fin in a box just ask me i'll fix it for ya

eat-your-vegies's picture
eat-your-vegies's picture
eat-your-vegies commented Tuesday, 11 Nov 2014 at 1:26pm

caml wrote: Ah correction there eyv , solid glass fins are almost exstinct . By far most common is resin transfer or semi plastic . Resin transfer are the honeycomb / carbon . But you mean the part of the tab where the grub screw fits is not soft plastic. I tighten my screws as tight as possible without stripping the thread . Often doing it for others whos fins are half hanging out of the plugs , unaware of this maintenance thats needed to keep up. The more movement there is means power transfer doesnt occur and also delayed reactions . If you have a loose fin in a box just ask me i'll fix it for ya

cheers buddy

a360's picture
a360's picture
a360 commented Tuesday, 11 Nov 2014 at 4:25pm

The FCS 2 systems is not user friendly if your are repairing outside a repair shop the other problem with the FCS 2 system is we are seeing a few issue with fine sand jamming the cam/tab and some fellas have damaged their boards trying to remove.
Futures have their own problems but we are talking FCS.
Seen a big spike in glass on fins lately maybe to do with being seen to be ''different''

mickj's picture
mickj's picture
mickj commented Tuesday, 11 Nov 2014 at 7:39pm

I'm getting stress cracks in the glass around the front of almost all my FCS II plugs (got them on 4 boards currently, and have had them on about 6 or 7 all up), splaying laterally across the top of the plugs.

Not impressed, couple of these boards have only been ridden a few times so not a lot of time in the water or multiple fin changes (you do need a reasonable amount of force to get them out I reckon).

That happened to anyone else?

I spent a few hundred bucks upgrading my fin quiver as well with these new plugs and I'm some distance from being convinced the system works. May also revert to glass ins.

udo's picture
udo's picture
udo commented Tuesday, 11 Nov 2014 at 7:47pm

Mickj, can you post some pics of the stress cracks, did your older boards with that style of plug also have stress cracks or just the most recent ?

caml's picture
caml's picture
caml commented Tuesday, 11 Nov 2014 at 8:08pm

For that problem is the glassers job to re- inforce the area with oval shape patches of glass matt . Theres a lot o forces going on in that area so appropriate glassing needs to be done before the board even gets in the waves . Custom made boards made by good craftsmen helps there not a production line model

eat-your-vegies's picture
eat-your-vegies's picture
eat-your-vegies commented Tuesday, 11 Nov 2014 at 10:10pm

mickj wrote: I'm getting stress cracks in the glass around the front of almost all my FCS II plugs (got them on 4 boards currently, and have had them on about 6 or 7 all up), splaying laterally across the top of the plugs.

Not impressed, couple of these boards have only been ridden a few times so not a lot of time in the water or multiple fin changes (you do need a reasonable amount of force to get them out I reckon).

That happened to anyone else?

I spent a few hundred bucks upgrading my fin quiver as well with these new plugs and I'm some distance from being convinced the system works. May also revert to glass ins.

you haven't been listening to uplift and working those glutes too much , have you. big legs big turns or whatever he goes on about lol ..... too much for those crappy fin plugs.

mickj's picture
mickj's picture
mickj commented Wednesday, 12 Nov 2014 at 2:32pm

Don't have the program to upload photos here sorry but this is a recent problem with FCS II plugs, all boards from the same manufacturer too.

If you're looking at the board laid flat on the ground in front of you then these stressies are splaying an inch or two towards each rail from the top of the plugs - between 2 and 4 per fin plug I'd say. Only a mm or two wide but definitely visible in the glass and guessing they'll just worsen until the plugs come loose unless reinforced. More inclined just to sell em myself and start again.

Cheers