I know this has been covered before but my google search of the forums only seems to be bringing up stripped inserts. Anyway I've been thinking of putting some outboard rear straps on my 2007 S-Type 93 litre to make it perform more like a slalom than a freeride board.
The boardlady shows each insert wrapped in PVC sheet then inlayed into routered hole with epoxy paste. boardlady.com/inserts.htm then glassing over etc.
Had a look on Whitelion's blog https://picasaweb.google.com/TimHemer/BoardBuilding7#5322491605642895282 and found this method where Kimba fits inserts with no PVC sandwich glued around but uses cloth pushed into routered hole with insert and epoxy paste. I assume holes are slightly larger than inserts to allow for cloth.
I understand the glassing over process etc but can I forego pfaffing around with the boardlady's method and just do it Kimba's way i.e. is it any weaker.
Any tips would be appreciated - even comments regarding whether it'll be worth doing to the board.
I'd be concerned* using this method to move straps more outboard as the forces would be so much greater perpendicular to existing inserts as oppossed to parallel with them (in relation to the long axis of the board).
A guy down here changed a formula central chicken strap to dual straps using carbon fibre strips. I *think* it worked out ok... Uh, Ads?
I can't imagine the forces involved with 94KG - I'm just a flyweight...
This is what I had in mind for the SL58:
Ooh now you've got me thinking Sheartip....I could use this method just to trial whether outboard straps would work on the board. Thanks for the great input. Longterm though if it works I'd want to fit proper inserts.
Sausage
When you come to actually bunging it in the hole, the glass cloth method is a bit harder and messier. Hard to avoid getting voids between insert and foam, I find it way easier to have a well buttered square (insert in d'cell block) and put it in a well buttered hole and then wipe off the excess.
With the glass over method I find it wants to move around, especially as ideally you need a skim of paste on the insert before you glass it, then butter it with paste, the glass wants to flop, it is crap.
Make sure you do it on a falling temp in the evening so expansion is not trying to eject your good work :)
I always use the board ladys method, and I like the idea that it has something else between the insert and the styrofoam. Lately I have been getting paranoid too, and adding divinycell on the bottom of the insert. My theory is that if a screw goes through the insert, then the divinycell will prevent water entry.
Most if not all the inserts I have removed from boards are just the fibreglass wrapped around the insert and bunged in, type of construction. In some of these boards, they have had leaky footstrap inserts, so take from that what you will.
I hate footstraps twisting, so on all the boards I have modified lately I have used double screw inserts to prevent this. I love them! All I have used is the regular chinook inserts spaced 1/2 inch apart using divinycell. I also only use 8 gauge stainless screws, as I figure if/when they strip the insert, I can always go to the next size up.
I hate trying to jam my foot into a twisted strap when over-powered.
If you are good with DIY, I think adding inserts is a good idea. I changed a Dunkerbeck designed Thommen board that I disliked into a great board, just by adding inserts where I wanted them. (Who would figure that a 6'4" guy has longer legs than a 5'8" guy )
Voids in between the insert and the foam does not matter.. Just open up a cobra board! I've had inserts (Fin,track and strap) just floating without any foam touching.. Perfectly fine.
I make a jig up and make the hole a few mm bigger than the insert and then just put some glass and thickened resin in the hole and push the insert in. Doubt there would be any voids unless the resin melts the foam. Which it does on a hot day.
I'm even skeptical about the glass. The screw will hold the insert to the deck.
Footstrap inserts, I figure, are only pulled on. So what stops them pulling out is the decks outer skin. If the laminate over the insert is strong enough, it's not going anywhere..
Putting PVC foam around the insert just means you're cutting a bigger hole in the board.
Snags, take a look at Mount Best web page where he made small extensions for his current board to give him room to move. http://mtbest.net/isonic50.html
brian i use a small dremel router, if anything go a bit tight and finish off with a file to make sure its a tight fit,probably the most important tip is to make sure you have sanded the insert with some rough sand paper,
i wouldnt worry about the divinicell because you probably havent got any, the best you can do is cut up some glass really fine and mix it into some araldite and glue it in, as long as the insert is a tight fit bash the insert down so its slightly proud of the deck, when the glue has starting to gel blend the overlap with the deck
when its cured give the insert a sand and glass over the too the deck
as long as you sand the insert and have a nice tight fit so the insert doesnt move you cant go wrong
Hi Brian,
I have never had any problems using the quick/light insert method. These have only been used on slaloms and speeds though and always with double screws. I have never pulled out a screw either, it is such a shame that most production boards don't use double screws. I always fully sand the inserts to remove mould release and key the surface and pre-butter them before insertion. The holes have some filler added before insertion to minimise plugging and voids. I have a router jig with adjustable feet so that the router slot is always positioned tangiental to the insert location on the deck. Tie-downs are used to hold the jig once positioned.
Another way to enhance the bond between the deck laminate and the insert laminate is to use larger pieces of glass around the insert so they sit high then spread them out on the deck(away from the insert) and tape them down flush with the deck using masking or sellotape. You need to chamfer the sandwich pvc (3mm in my case) so that the laminate flows nicely onto the deck and is not folded sharply. This also allows more filler to bond to the deck around the insert and in most cases you have minimal sanding and cleanup. Finally, make sure that the holes are countersunk larger than the major diameter of the screws being used, if it isnt CS the deck laminate will crack and the screw will delam the deck from the insert.
In your case adding outer inserts can be concealed by the pads allowing more reinforcement to be added and hidden.
Cheers, Tim.
Basically putting a pvc block into the board first make the insert stronger, the insert bonded to the block has pretty much no chance getting pulled out through the deck unlike just an insert, which i have seen alot of times.
Also if you make the cavity around the block or the pvc bigger than a snug fit you run the risk of melting the stro core as the resin tends to heat up more if you have a big chunk of it together..unless you get a slow cure resin where the heat up is less intense.
Guys,
Thanks so much for the invaluable advice and tips. I'm leaning towards Kimba's method as I have no PVC sheet readily available (can you buy small sheets and if so, where from?) and as the inserts will be concealed under the pads I'll be able to beef up glass layer on top.
Also I assume the chinook 2 hole inserts are spaced close enough so you can use 2 screws to fit footstraps.
i can mail some if you want but the problem with the foam(boardlady.com/inserts.htm) is you have the insert then foam then the deck laminate, meaning the insert is lower than the deck, all you need is for the glass to lift a tad under the insert and you have the pvc and suck suck suck a wet core
Hey, what the heck, here is a photo of when someone went crazy and added all these inserts to their board!
Result? The footstraps are exactly where I want them, and the footstraps can't twist! Woohoo!
I did this for kite boards, but used to put inserts into Windsurfing boards the same way while I was making my own. http://www.kiteboard-independent.com.au/index.php/board-mods
I found that sandwich windsurf boards had the plugs in blocks of diviny cell or straight in the poly styrene, the whole diviny cell block tends to come loose as there is no give in the PVC foam, this is on high impact wave boards.
Best method I have foand is to use a block of poly urethane surf board foam, as this stuff is flexible and will absorbe some of the strain. If you cant get some from a surf board shaper try filling the hole which is 2-3 times bigger than the insert with PU foam in a can from Bunnings and keep on stiring it down for a while to compact the foam, then resin in the plug when the foam has set.
remembering the plug is under the deck and only a thin layer of bog between the divinicel and the corel, the bog looks like Qcells and they can be "porous" you should only use silica airosil to make a water proof glue
remembering the plug is under the deck and only a thin layer of bog between the divinicel and the corel, the bog looks like Qcells and they can be "porous" you should only use silica airosil to make a water proof glue What are you trying to say?
What are you trying to say?
keef,
Thanks for the offer for some PVC - I reckon the 5mm thk would be all I need although having a think about it, if I only use the fibreglass with resin paste (or araldite) you are effectively making (for want of a better term) a swimming pool for the insert i.e. even if the glass splits from the top of the insert you still maintain a water tight seal from the layer of glass thats been pushed in with the insert and folded outwards over the existing skin (as per Kimba's advice). I think the real benefit of the PVC sandwich around the insert is to give a larger bearing point as it is effectively wider.
Anyone want to do it for me?
PS - Keef, is this the araldite you are referring to or is it a different product? http://www.selleys.com.au/trade/specialist-products/epoxy-adhesives-fillers/araldite-super-strength
Keef, i was not saying what was in the bog mixture or the procedure which to put the insert in.
I explain for you, not as a stab at your comment just to give a better picture.
Glue the pvc block into the board, a good mix for the bog is a "glue powder" maybe a little bit of q-cell just to make it thicker.
Once the "bog" has cured, rout out the hole for the insert, chinook ones are the best.
Sand the hell out of the insert with 40 or 60 grit sand paper so you have no shinny bits left.
Make some more bog like before and also some straight resin. put bog in the hole and on the insert, also in the cavity in the underside of the insert. stick it in the hole so there is no gaps, now glass over it with 3 layers of glass and the straight resin mix, 1 layer of glass goes to waste in sanding..
If you glue the insert in and glass at the same time it all bonds together making it stronger.. if the insert was sanded enough on the top it should not deleminate in the future.
If epoxy will "never" bond to the plastic, every fin box, deck box, or strap insert in every board ever made should stuff up.. which it don't..
One handy tip is to bevell the screw hole in the insert a bit once it's all finished so the screw don't pull the glass away from the top of the insert.
Just out of interest, has anyone tried to lay carbon over an insert? Is there an easy way to find the hole afterwards? With glass you can see it.
I resorted to using toothpicks, to stick out a little bit, but there must be another way.
