Bedding parts to mast section...

[paxfish]

Hi Gang, I am about to mount a sprit socket to my forward crossbeam. I could simply slather it up with 4000 UV and bolt it on, but I wonder if there are any tricks to getting a nice professional even layer of bedding material with a clean edge?

The concave surface conforms very closely to the profile of the crossbeam mast section. Here is the part:

 

[Tom.151]

Maybe cut a gasket from something like a thick truck fender flap?

 

[paxfish]

Even though most of the forces on this thing are in compression, I think I want the added security of a medium adhesive like 4000 UV to augment those 1/4" bolts...

 

[gonzo]

The trick is to tape the part to be mounted, then leave an even margin and tape the crossbeam. After the bedding compounds oozes out, make a nice fillet and take off the tape.

 

[Chuck Losness]

Put a little mineral spirits or turpentine on a rag and then careful wipe around the fitting. The excess goo will come right off leaving a nice, neat clean edge. Works every time for me.

 

[PAR]

Both Gonzo and Chuck have given the usual and correct advice. If you need a "bed", tape it off carefully, apply a generous bead of goo, knowing much of it will ooze out when you take up the machine screws. When it has oozed out, a solvent damp rag will clean the seam nicely and if you're careful, you can make a little fillet too, before peeling the tape, leaving a crisp line around the seam. Conversely, you can skip the tape and just wipe the ooze out, again with the damp rag, though the seam will have less exposed sealant visible.

If the fit is close, but not perfect, you can make it perfect, which will transfer loading better. You'd do this by "bonding" the part, to the cross beam, with epoxy. This doesn't have to be a permanent mounting, you can coat the beam and the back of the part with wax, bond it down, then pop off the now perfectly shaped epoxy piece, which is then bedded in the sealant of choice, after the wax is removed from the beam and part.

 

[UpOnStands]

is your cross beam aluminum?
what thickness?
tapping the beam to take the SS screws?
simple, yes. long-term?

 

[PAR]

Given the loads typical, I'd bond the socket, to insure as much contact patch as practical is available.

http://www.westsystem.com/ss/bonding-hardware/

 

[paxfish]

Thanks for the responses everyone. I'll post up a pic once I have everything mounted and bobstays attached.

 

[paxfish]

done - thanks!

Done. Thanks for the suggestions on the mount. 4000 adhesive UV was my choice.

http://i.imgur.com/HzJIC2i.jpg

 

[paxfish]

Just to close out this thread, here a couple of pictures of making a nice base for a cleat on a curved boom. The excess was removed and I made a nice fillet. The bottom of the piece and the fasteners are coated with wax and the tape was removed before curing.

Thanks for the tutoring, Guys!