Sealing a cored hull
#1
Sealing a cored hull
I'm installing a thru hull for a A/C water pickup and not sure if the hull is cored or not at the location I'm considering. I'm assuming the whole bottom is????
Fountain has not returned my call with this info.
Is there a way to tell if it is cored or not just by looking w/o drillling a test hole? If it is cored, do I dig out as much of the coring as possible and fill with epoxy? What determines the use of a backer block? I'm not planing on the flanged seacock style that gets screwed thru the hull, but a normal thru hull with a inline valve that screws on top of the thru hull.
And finally, I have to make the thru hull fitting do to a special application, I know bronze seems to be the normal, is there any reason I can't use SS? Fresh water use only.
Any help would be appreciated.
Thanks
Fountain has not returned my call with this info.
Is there a way to tell if it is cored or not just by looking w/o drillling a test hole? If it is cored, do I dig out as much of the coring as possible and fill with epoxy? What determines the use of a backer block? I'm not planing on the flanged seacock style that gets screwed thru the hull, but a normal thru hull with a inline valve that screws on top of the thru hull.
And finally, I have to make the thru hull fitting do to a special application, I know bronze seems to be the normal, is there any reason I can't use SS? Fresh water use only.
Any help would be appreciated.
Thanks
Last edited by US1 Fountain; 12-23-2006 at 11:30 AM.
#2
Re: Sealing a cored hull
Doing some research on the net with the West System. From what I've gathered on working with cored hulls, after drilling the hole, the coring must be dug out (how much additional?) around the hole between the inner and outer layers, then that void is filled with the West System epoxy. Do I need to use any type of filler such as the 404 high density filler, or just the epoxy mixture itself? I'm assuming the epoxy also gives the hull some strenght to prevent the thru hull from squashing the hull when tightened.
Just needing to know if I'm on the right path.
Just needing to know if I'm on the right path.
Last edited by US1 Fountain; 12-23-2006 at 11:22 AM.
#3
Registered
iTrader: (3)
Re: Sealing a cored hull
yep, you need to clean out a bit of core..not much, just enought to get some epoxy in there to seal it (the coring) and yep you want to use some filler and the epoxy/filler will resist compression squishing better than a balsa or foam core, though you dont really want to put massive amounts of torque on a thru hull..
#4
Registered
Re: Sealing a cored hull
US! Fountain,
Your hull is layed up with Vinylester resin. IMO, I wouldn't bother with the expence of using West system epoxy. Instead go with Vinylester resin. There really isn't a delamination or strength issue here. It's very basic.
In all reality, there is no need for anything other then 3M 4200 5200 Marine adhesive/sealant. If prepared correctly.
But if you want to go the extra mile. Do what the others said about carving out a little ( 1/4" ) into the perimeter of the hole. Catalizing some vinylester resin and mixing some cab o sil or other filler untill you get a creamy consistancy. Fill the void and wait for it to cure. Sand area, and install Thru hull fitting using either 3m 4200 or 5200. And as Phragle said, you dont want to over tighten the fitting and squeeze out all the sealant. That is a mistake too many people make.Use sealant sparingly. Wipe off excess with Acetone and your done.
Rick
Your hull is layed up with Vinylester resin. IMO, I wouldn't bother with the expence of using West system epoxy. Instead go with Vinylester resin. There really isn't a delamination or strength issue here. It's very basic.
In all reality, there is no need for anything other then 3M 4200 5200 Marine adhesive/sealant. If prepared correctly.
But if you want to go the extra mile. Do what the others said about carving out a little ( 1/4" ) into the perimeter of the hole. Catalizing some vinylester resin and mixing some cab o sil or other filler untill you get a creamy consistancy. Fill the void and wait for it to cure. Sand area, and install Thru hull fitting using either 3m 4200 or 5200. And as Phragle said, you dont want to over tighten the fitting and squeeze out all the sealant. That is a mistake too many people make.Use sealant sparingly. Wipe off excess with Acetone and your done.
Rick
Last edited by FX10; 12-28-2006 at 12:32 AM.
#7
Re: Sealing a cored hull
I'm waiting on some ordered parts so I can do my layout, then drill the hole in the right spot.
Thanks.