Drilling through hull

extremeh2o · Newbie Joined: 05 Mar 2003 Posts: 39 City: Carrollton, GA

What is the best way to drill through the hull? Shocked

Any particular bit, etc.? We're installing a custom ballast system in our boat and need to drill an intake for the fill pump.

driftwood · Posted: May 15, 2003 11:57 am Post subject:

tape off the area inside and out with masking tape = preferably several layers thick. Drill a pilot hole from the inside out then go to the outside and drill with a hole saw - dont push hard or you will make a mess.

The masking tape will help prevent chipping the gelcoat.

arlanj · Newbie Joined: 07 Apr 2003 Posts: 31 City: The Plains

An old carpenters saying:

"Measure twice, cut once"

You can't afford a mistake, check, double check, and check it again before you cut a hole in your boat. It gave me the "willies" to cut a hole in the bottom of my boat for my Perfect Pass paddle wheel.

extremeh2o · Newbie Joined: 05 Mar 2003 Posts: 39 City: Carrollton, GA

Thanks for the tips! I guess I'll bite the bullet and go for it.... Confused

MrBlean · Posted: May 16, 2003 5:08 am Post subject:

Why not take the ballast feed from the upstream side of your engine cooling pipe? That way you just cut a rubber pipe and insert a T fitting rather than have the worry and hassle of cutting into your hull? Of course, you'd need to check that the ballast pump flow didn't starve the engine (unlikely) and this would be so eqasy to do it's worth trying before getting the drill out! I've seen references to many DIY ballast systems that use this method and it's the one I plan to use for my own.

X-Star · Soul Rider Joined: 01 Apr 2003 Posts: 253

I'd like to see start to end pictures if you got em. I'm thinking about adding another system to my boat and wanted to see if others were having success. I'd use the stock balast fill hole in my boat but I cant see my system filling very fast trying to fill up 7 bags and tanks. Let us now how it turns out.

MrBlean · Posted: May 16, 2003 8:45 am Post subject:

The system I intend installing on my Prostar 205 open-bow will use sacs front and rear but will be hard-plumbed using a Jabsco reversible pump as used on factory supplied systems. The factory systems may use more than one pump but the input and output on these pumps is (I believe) only 1 inch diam so, on a single pump system, provided the input hole isn't smaller, there's nothing to be gained by making it bigger than the pump orifice.

There have been some intereting articles on DIY ballast systems notably http://www.wakeworld.com/Articles/2001/BallastSystem1.asp
This is where I have gleaned the idea of using the engine feed rather than drilling a hole in the hull.

boehnkew · Outlaw Joined: 26 Mar 2003 Posts: 112 City: Kennewick, WA

I agree with MrBlean. As long as you keep an eye on your engine temp when filling, why not use the existing water intake? At least try it to see what happens begore drilling. I'm also planning to connect the drain to my bilge drain. It might add a couple of minutes to the fill/empty time, but no biggie to me.

Let us know how it goes.

MrBlean · Posted: May 16, 2003 11:14 pm Post subject:

Willy

I agree with that idea too. The fewer holes in the hull, the better, especially if you have to drill 'em yourself! I jkust hope these suggestions haven't come too late for extremeh20

extremeh2o · Newbie Joined: 05 Mar 2003 Posts: 39 City: Carrollton, GA

I still haven't drilled the hole yet. I originally debated on using the engine cooling intake. However, according to the install on the WakeWorld site, larger pumps could wind up starving the engine of water. I'm using a 2000GPH pump to take in water. I would hate for it to suck up all the water before the engine had an opportunity to get any. Confused

MrBlean · Posted: May 23, 2003 5:48 am Post subject:

extremeh20

I understand your caution so here's a suggestion....

Install your pump into the take up line as suggested but put the outlet over the side. Take one of the water feed pipes off your engine manifold, point it in the bilge and run up the engine whilst afloat. Be careful, you'll be amazed how much water the impeller delivers and how much flows thro' your engine. It will fill a large bucket in a few seconds so don't think you can use this option! Then switch on the ballast pump. If, after doing so it's delivering water over the side into the ake but there's no water coming out of the feed to your manifold or if it's seriously reduced, yep, you've got a potential problem with starvation. This "experiment" will be far quicker and less stressful to you than drilling a potentially unnecessary hole in your hull. At least you'll know if you have to bite the bullit and get on with it!