I’m mentally preparing to build this kite hydrofoil board with two layers of carbon fiber on top, maybe 3.
Anyway, my plan is to melt some wax into the strap insert screw holes, but how do you find the holes with precision after the carbon fiber sets? Take damn good measurements? somehow use a pin barely above the surface of the board to cause a small buldge?
I’m curious if there is a best practice for doing this, thanks.
what style of insert? will you be reinforcing with High density foam or wood at insert site?
I was thinking on the lines of these:
http://www.theshapingshack.com/3-post-1-4-20-foot-strap-insert/
I guess they may already have a filler inside the metal threads. I may also 3d print my own and press fit a stainless steel nut into the print very similar to these except rectangular and with 3 nuts for variability: https://youtu.be/HRb3KYw0S-g?t=14s. Was going to epoxy them into a cuttout area of the 50kg/m3 xps blank I am making or pour some 8lb hd foam around the pocket while they sit in there. I’ve got a large foam block with my track inserts laid into already and I have to put that inside the bottom tail of the board using epoxy and either cabosil or qcell filler. I’ve heard the qcell is sandable and probably preferred but the cabosil is stronger and not just a mere filler. Either way I think that will work. I’m using all epoxy so no poly b/c I don’t want to deal with the nasty fumes althought I have a full mask for the sanding and cabosil work.
Anyway, I’m kinda prepared to make some mistakes and begin really learning the hard way, but I’m at a road block on how to find the insert holes with some degree of accuracy when after you laminate with carbon fiber only. Any tips of this and other things I mentioned are appreciated, thank you.
When I glass boards with heavy opaque glass jobs I mark my fin placement for boxes on the foam and stick a pushpin at the very top and bottom on the line. This creates a bump - sand off the glass and expose the ends of your placement lines.
Route in boxes no problem.
Fill the holes with wax (maybe something stiffer like foam would be better) and stick a little pin in the top. Sand it open when the time comes.
Wide awake,
I’m a rookie, can you link me to an image of what type of pin you are referring to? Also, I’d guess the height of the pin above the board should be very small… Maybe 2mm at most?
Steel set screw in each hole, tape over, glass, and use a magnet to find the set screws.
Thanks… I just tested that bc I have some small disc 4mm magnets around and it works well… The magnet snaps into place. Much appreciated.
JM has the ticket!
I place the high density inserts with epoxy and milled fiberglass. The inserst are larger than actual strap plugs going into the foam. 5 pound corcell foam is fine and inexpensive and easy to work with compared to 8lb density pour foam. I get the foam core back to origianal intented shape. Vacuum bag your carbon fiber on. Get board to the stage you have one last coat of resin to finish. Drill insert openings and with epoxy abnd milled fiber slurry to set inserts. Put a clear fiberglass and wet out over plugs, the plugs that take a screw or the ones that take a machined bolt(those have a wax covering). You could add pigment color the resin with the actual insert black to match CF. Sand everything off nice. Tape off if necessary for final coat of resin. Sand and polish. Simply put, you can put the inserts in after you vac bag the CF. The preplace reinforcements are already in the blank. It is the last step before final coat of resin. I think you are over thinking it.
You are so clever. Stop it. (Ha)
All the best
Yeah I’m doing mine after the carbon lam. In a HD block.
All the best
Thanks for the input. I’m gonna try the magnet and go your route if that doesn’t work I think. I’m gonna do a test piece that is 6 inches in length, I’m tip toeing into this crazy world.
This is how it was done on Sailboards for years and in my opinion the best method.
BB30 offer great advise. I like to use the 1/4" x 20 single post inserts that you can get from Fiberglass Supply. I install them post hot coat prior to the major sanding. Here is a link to the inserts: http://shop.fiberglasssupply.com/cartadd.cgi?sku=R66-6101. Uncle D
Set the insert slightly proud. Those inserts have a buit in tab that makes it handy for doing this.
Once the deck pad goes over it, nobody can tell. It all looks flush.
It’s how I do all my vac bagged carbon boards. It’s just easier.