Cabin hull screws

thataway · Posted: Fri Nov 14, 2014 6:49 pm Post subject:

I do not feel that it is necessary to use "two" epoxies. What you can do is to take a "Q" tip and dip it in the epoxy after the two parts are mixed, before adding the thickening agent to coat the hole, this takes a few seconds. (See my note about the migration of what Sunbeam calls "neat" epoxy vs one of the low viscosity epoxies [such as Clear Penetrating Epoxy Sealer--CPES], which migrates far better into balsa core than one of the usual laminating epoxy, such as West 105.)

You should not add thickening agents until you have mixed the epoxy, so there is no extra step. The epoxy has enough pot life to allow this and then thickening, and further use.

I recently put a Jabsco galley pump, in the water line from the water tank before the foot pump (it allows water to flow thru, with minimal loss of volume. I did not use their switch or spout--kept the old one). This was to empty the water tank at the end of the season, or when shocking it. There is a monetary switch, which can be pushed with a finger or kept down with knee pressure, on the face of the galley cabinet.

I filled the "C" clamp holes and left the hose loose as Sunbeam described.

CDory23 · Posted: Sat Nov 15, 2014 7:08 pm Post subject:

Ok, So I have removed screws and drilled overdrilled holes to 5/32. I placed a piece of tape on the bit to not go too deep but i noticed one hole is about 5/8" deep. I have also bought "Smiths" CPES.

Do i need to be concerned with the one hole that is 5/8" depth? Was my diameter that I overdrilled large enough? Also for the undercutting what bit is the best to attach to the dremel? A routing bit?

Thanks.

Sunbeam · Posted: Sat Nov 15, 2014 7:49 pm Post subject:

CC Rider · Posted: Sun Nov 16, 2014 12:21 pm Post subject:

I am going to be adding shelves and possibly some drawers to my galley under-sink storage area this winter, and the elimination of the rather cheesy factory-installed, screw-into-hull steel L brackets is one of my targets.
This may be a dumb question, but I was floating the idea of using 3M5200 to bond a piece of marine plywood to the hull to act as a cleat. The cleat would be about an inch or so in height. Then, screw through the cleat to the cabinet side.
Is the use of 3M5200 for this purpose ill-advised?

Chris

Captains Cat · Posted: Sun Nov 16, 2014 12:25 pm Post subject:

Only if you never, ever want to take it off again. Rolling Eyes

Charlie

thataway · Posted: Sun Nov 16, 2014 1:17 pm Post subject:

I have used both 5200 and epoxy. There are some pluses to quick set epoxy. It goes off faster, and adhesion is better than 5200. With either, I would suggest that you sand the hull, I would slightly thicken the epoxy. I have used hot glue to hold the wood cleat in place until the epoxy or 5200 goes off.

I do this frequently--and it works well for a place to set screws into the side of the hull.

CDory23 · Posted: Sun Nov 23, 2014 12:11 am Post subject:

Speaking of 5200. Why not just use it to fill the cabin hull screw holes I"m speaking of? Or using it as a filler after using CPES? Is it purely for the viscosity reasoning that the CPES will fill voids/gaps, flow into harder to reach places therefore attach better providing a stronger bond?

Also, I may need to start a new thread but I'm removing an older GPS antenna that is mounted on the roof with 4 thru roof bolts. I was considering using 5200 for filling these holes. I"m not too concerned with matching the gel coat on the top since it will never be seen and the inside texture seems to be almost impossible to match.

thataway · Posted: Sun Nov 23, 2014 2:25 pm Post subject:

5200 is clasified as a sealant, with adhesive properties. It is not intended to fill gaps or holes. (Although used for this at times). When 5200 adhers, it is a good adhesive, but there are times it does not adhere.

If you look at the technical bulitins for 5200 (all of the 3M materials) There is a table for adhesive properties. It is not as good as epoxies by a long shot.
I personally do not use CPES in the filling of hull screw holes. If it is dry, there is not reason--and the use of undiluted epoxy is optional.

As for the filling of previus holes inn the deck, there are several reasons not to use the 5200--including it will discolor with time (4000 does not discolor as much, but is even a poorer adhesive).

For bolt holes, I would want to use some structurel material--such as glass fibers if the hole is 1/4 inch or larger. Gel coat can be used with epoxy-and in small areas, a gel coat paste color matched is probably a good product to use. There is also the option of using thickened epoyx, then using a Dremel tool to contour the surface to replicate the non skid surface if necessary--finally liquid gel coat to finish. There are other ways, including using non skid pattern molds, making your own mold, and dabbing on thick gel ccoat paste then contouring it.
Perhaps the best product is vinyl ester resin, which is compatable with gel coat, and stronger bond than polyester resing. There is a lot of personal prefernce--but I would never use 5200 as the primary filler for a hole.

ssobol · Posted: Sun Nov 23, 2014 3:11 pm Post subject:

I just put bolts or screws with washers through the holes. Truss head screws/bolts can also be used without washers. If the screw/bolt comes into the interior I just put an acorn nut on it. A sealant of either 3M 4000 or butyl tape works fine to seal the screw. You can use 5200 if you are sure you won't ever need to get the bolt out.

Given the utilitarian look of the C-Dory interior having a couple extra screws or bolts showing isn't noticeable.

It is a lot easier to put a bolt/screw through the hole than mess around doing a FG repair and gelcoat fix.