JUst gave my new quad EPS Epoxy a maiden voyage ride and it is an awsome fast board!! tried about 5 diffrent fin set ups and my favorite was MR FCS twins with smaller longboard side bit trailers. the only problem is the fins blew out. Had them set with 3M 5200 and glassed over top of plug for strength.
Has anyone used these fins they are alittle bigger fin and lots of tork on them at high speed especially off the bottom and cut backs. I sure would like to use them in an FCS set up. I drilled out the new plugs bummer $40 down the drain and thinking or resetting them slow cure epoxy!
Sould I waste another $40 on plugs or glass a set of these fins on? I would hate to do this as the whole idea on this board was to experiment with diffrent fin configurations. I really don’t like the other box fin set ups I know all about them have installed them all doing ding repair work and like the ease of FCS install and repair.
Can you get another slow cure Epoxy other than RR I have the fast hardner but not happening on my test results to hot!!
The stuff is’nt that riged it gives and on a hard turn it gives enough to break bond on the surface.
I installed the plugs the way they are supposed to be installed have done at least 1000+ but not using these materials, this is a new animal. although the 5200 is tough shit it still gives and the deeper profile of these fins give enough force tork to move this material.
What density is the EPS? if it’s 2# or under, you might have to put in Core-cell or D-cell inserts, bond them to the deck and glass over to tie them to the bottom and then mount the plugs in the inserts. If you are worried about cosmetics (Core-cell is a cream colour, D-cell is usually brown or green) you could use Roha-cell which is white. The plugs are designed for higher density PU foam. Putting in MR’s might be pushing it a bit with lower density EPS foam.
Did you use the 5200 fastcure, or the 5200 standard stuff. If you used the standard stuff, it takes about 8-10 days to cure. It will be stiff on the top, but soft as the day it came out of the tube underneath. Did you rush to surf that board?
I’ve found out that the 5200 fastcure gives the fin setup a bit of spring coming out of a turn, the 5200 has just enough flex to allow the fin box to load up a bit, but still super strong, and firm. I’ve been using it with ProBox and haven’t had any problems yet. You must have one hell of a bottom turn? I even took a direct hit to the front portside fin a few days back, super high tide and I thought I surf all the way into the rocks, took a gash out of my plastic FCS fin, but didn’t hurt the box or board???
One other thing, I’ve been using a dovetail bit to cut my fin holes. The extra width at the base of the box really holds the boxes in. You shouldn’t need to d-cell, or patch anything in on the softer EPS…just make sure your glass job around the fin area is solid, none of those sand through like yo mama did.
If it is 8 to 10 days to total cure then yes I rushed!!!
Since my original post I have removed the plugs and it was not completely cured. Maybe 90%
Still new to all the EPS epoxy stuff and yes it is #2 density. I Have never made an epoxy board before so every day for the last week has been like Christmas The learning curve and experimentation making the board and then riding it has been awsome!!!
I’m still worried about the strenth using those MR twinnies!
So I already went into reinforcement!
I have Balsa so I made some nice plugs and will insert the FCS into them it also looks really cool with the Balsa glassed in and Balsa is lighter than the #2 density foam it seems!
I used the 5200 to set the balsa plugs did a nice seal around the entire cavity where the balsa plugs will go.
Now that I have an idea on the complete cure time of the 5200 I think this could be a very solid set up.
One of the reasons I really want to make sure these fins stay in is that I spend 3 months in Baja every year and I don’t want to be making fin repairs due to over powering a turn!! We shall see I’m itching for the winter season and leave in 3 weeks.
Anyway hope this works!
If anyone thinks this won’t work let me know!
Thanks for feed back I will try and take a shot of the Balsa plugs because it looks pretty cool!
I used the fast cure and it was 2 days after setting the plugs and the weather was very warm here Encinitas San Diego, So I was surprised to see some of the Fast cure was not fast cured!!
I’ve gotten away from FCS and gone to Probox, so it an easier installation form the start. But if I was using FCS I’d do it the same way…use the H pattern.
Just treat the 5200 fastcure the same way as a resin set. Also fastcure cures in 24 hrs, dries to the touch in about 1 hr…depends how dry it is.
I put a football patch under my glass to add a cushion for sanding mishaps. So around the fin boxes it’s 2-6oz