Comp tip repair materials

I have a small horizontal crack in my comp tip about half way up. The crack is hairline and about 3" long perfectly centered on the leading edge. I think putting two layers of cloth and epoxy resin should be sufficient to ensure it doesn’t propagate.

What type and thickness fiberglass cloth should I use? And where can I find epoxy resin in pint size?

You probably don't even need the cloth. From your description, the crack is on the mold part line. Use a Dremel tool to open it up a bit and fill with thickened epoxy. Paint black to give it some UV protection.

If you were going to use fiberglass cloth, use 2" tape - most are 6-8 oz per sq yd.

You can get small quantities of epoxy at any hardware store. Most of those will be very viscous and make the glass hard to wet out. Heat will reduce the viscosity, but will also accelerate the cure time.

I just keep a set of WEST System group A (the smallest) resin/hardner & pumps on standby all the time. The stuff lasts for years if you store it properly.

You must coat the epoxy with paint or mix in a UV inhibitor or it will turn yellow and chalk up in the sun.

Hi,

I have a 1984 H18 that had one of the early production "CompTip" installed when they were introduced ..... now by about 2005 my comptip was a "dull" black and getting furry from UV exposure. I used West Epoxy (just like Matt suggests) to fix any dings/imperfections, sanded the comptip "fair" and smooth again w/ wet/dry sandpaper and then I painted the comptip white w/ Krylon "Fusion" spraypaint to help w/ UV protection ....

Before the comptip was "HOT to the touch" in bright sunlight .... now it remains "cool to the touch" ....

And when De-rigged .... keep the comptip covered w/ "Comptip Cover" .... there are several companies offering very nice covers .... I am currently using one from "Murrays' ..... ( my boat sits all summer "Mast-up" down at the Yacht Club ... and all winter at home on the trailer, "De-rigged" in the backyard)

_________________
HarryMurphey
H-18 mag/ #9458
Fleet 54 Div 11

Here is the crack


Ill probably will add the cloth due to the high force in that area wanting to pull it apart. Would you grind the crack out or just smooth the surface and wet the cloth over it?

If I were you, the first thing I would do would be to step the mast, put the boom on, connect the main halyard to the clew fitting on the boom, hoist the boom up about 3 feet in the air, and put the main blocks on. Set the mast roation to zero so that the crack is towards the front and crank on the mainsheet. Then flip the boat on its side and inspect the crack. If the crack spreads at all or shows any sign of failure, replace the comptip. If it looks the same as it does in the picture, do nothing.

Chances are its just a surface crack and nothing else. But if it does spread open or get worse when you pull on the mainsheet, a couple layers of fiberglass isn't going to fix it. No way I would grind into the comptip. If it's just a surface crack and you do that, you'll be cutting into good fiber and damaging the mast.

Inspect it under load. Then decide what to do.

sm

srm is correct...inspect it under load before using...a failure during sailing would likely result in substantial damage$ to your sail.

Might be a good idea to have someone rotate the mast a bit each way while loaded up as you watch the crack to see if this changes things as well.

Ya, I concurr ..... I believe Matt thought (as I did from the origonal post) that the crack was vertical along the centerline mold seam .... that is a "horizontal" crack .... across the mold seam ...... BIG DIFFERENCE .....

INSPECT UNDER LOAD!!!!

_________________
HarryMurphey
H-18 mag/ #9458
Fleet 54 Div 11