Tool for clearing out wet core

Lucky Day · Posted: Tue Apr 29, 2008 6:59 pm Post subject: Tool for clearing out wet core

Is there any particular hand tool that works well to muck out wet core from a cockpit deck? Or a particular power tool?

Wandering Sagebrush · Posted: Tue Apr 29, 2008 7:21 pm Post subject: Tool

In another boat group (Montgomery Sailboats), I have heard of people using things like an alan wrench that is chucked up in a drill. Drill the initial hole, then put the alan wrench in. No personal experience.

Steve

Captains Cat · Posted: Tue Apr 29, 2008 9:04 pm Post subject:

A dremel tool works well too.... Thumbs Up

With a wheel of sorts on it.

Charlie

Lucky Day · Posted: Tue Apr 29, 2008 9:29 pm Post subject:

I have never attempted anything like this. I want to work on the cockpit deck. I have removed the hatches and the fuel sender inspection port and have found water damaged core around all four openings. I want to clear out the bad core by going in from the side -- from the cross-section of the sandwich that is visible after removing the hatch assemblies. I looked at dremel tools on Lowes.com How would I choose a particular one? - and will it work going after the core from the side - rather than drilling in from the surface?

thataway · Posted: Tue Apr 29, 2008 10:10 pm Post subject:

You are not going to do a proper job from the side--if it is as great an area as you suggest. The allen wrench, Dremel tool, bent coat hanger is good for about 1 inch max. If there is more bad core than than, you will have to cut off the outer deck, leave the inner skin, recore with a synthetic or balsa. See my photos on the 25.

MOOSE · Posted: Tue Apr 29, 2008 10:12 pm Post subject:

I've used the allen wrench chucked in a drill method and it works fine.
Al

thataway · Posted: Tue Apr 29, 2008 10:32 pm Post subject:

One other thought, if you want to try the Dremmel tool route, and it is not too great an area, then you can use a flexable shaft. You can work the bit and shaft in several inches and still have good control. I prefer the Roto Zip with flex shaft--same company. There is more torque and it seems more substantial than the Dremel tool flex shaft.

Cutting out the top deck is not as hard as you might think, and texturing gel coat with silica will make new non skid to blend in where the cuts were made. A Fein saw would be best for cutting, but there are several (like Makita) very narrow blade circular saws (also Rotozip makes a very fine saw blade which will work on the deck for cutting off the top layer, if that is necessary.

thataway · Posted: Tue Apr 29, 2008 10:32 pm Post subject:

One other thought, if you want to try the Dremmel tool route, and it is not too great an area, then you can use a flexable shaft. You can work the bit and shaft in several inches and still have good control. I prefer the Roto Zip with flex shaft--same company. There is more torque and it seems more substantial than the Dremel tool flex shaft.

Cutting out the top deck is not as hard as you might think, and texturing gel coat with silica will make new non skid to blend in where the cuts were made. A Fein saw would be best for cutting, but there are several (like Makita) very narrow blade circular saws (also Rotozip makes a very fine saw blade which will work on the deck for cutting off the top layer, if that is necessary.

doc · Posted: Wed Apr 30, 2008 2:18 am Post subject:

Sounds like an epidemic. I have been spending the last couple weeks dealing with wet core secondary to lack of sealant on the cockpit hatch screws and inadequate treatment of the balsa edges. I have tried various methods to cut back the balsa to dry wood and what worked best for me was an aggressive burr rasp on a drill motor and a very sharp chisel. The chisel actually worked best if I scraped it back and forth over the grain of balsa using brute force. I ended up going back about one to three inches, mostly about one but there were some deeper pockets of wet core. I then sealed the balsa with West epoxy, used layers of wetted out glass and layers of thickened epoxy and set clear fir into the edges with pre-drilled oversized screw holes filled with thickened epoxy into which the new screw holes are drilled. Its been a TPITA and I have to agree with Dr. Bob that it likely would have been faster and easier to cut out the deck as he did and replace the core with foam. Next time. Over all though, due to Bob's past tutorials I think I was able to get a pretty good fix that should work for some time. At least I have the confidence to do further work if I need to. Prior to the cockpit deck, I removed every screw and bracket into the hull, glassed in the cabinets, and drilled and filled the screw holes. I bet I pulled a hundred or so screws out and learned to contort myself into ways I didn't think possible. This whole deal has made me very aware of the potential for further damage to the core to the point that it keeps me awake. Should I be pulling the brass stem protector and making sure water isn't getting in there? I also have a leak from the cabin handrail and radar arch that need repair before she launches for the summer. I will try to post some pics in the next few days.

doc · Posted: Wed Apr 30, 2008 2:27 am Post subject:

By the way. If I knew then what I know now, I would have pulled all the decks and screws before I ever put her in the water and sealed and bedded things up before the fact.

Doryman

Lucky Day · Posted: Wed Apr 30, 2008 11:47 am Post subject:

Warren - I found the wet core when I pulled the hatch assemblies to work on enhancing their watertightness. As soon as the covers were lifted out of the deck, the water intrusion was very clear to feel and see. You also might find that the hatch screws are loose in their holes.

Bob - do you know the specs on the Nidacore I would use to replace the balsa?

Lucky Day · Posted: Wed Apr 30, 2008 7:54 pm Post subject:

Regarding the Nidacore question I posed to Thataway --

I found Bob's original post describing the process and materials he used to rebuild the cockpit deck on Frequent Sea, his CD-25. If you read through the thread, you'll find a wealth of information regarding water intrusion in some of these boat's cockpit decks.

Here's the link
[URL=http://http://www.c-brats.com/viewtopic.php?t=5823&highlight=[/URL]

thataway · Posted: Wed Apr 30, 2008 11:16 pm Post subject:

The Nada core is not quite as stiff as balsa, but more than adequate to do the cockpit floor. Since Nadacore has glass fibers embeded in the surface, it bonds well to other glass, with either polyester or resin. The Nadacore is available in 1/2" to 3/4". It is a hex cell composite. I don't have the full data with me (I am traveling in Calif.--but it is available on the internet. I used one 4 x 8 foot sheet to replace the majority of the cockpit floor. It was 3/4" thick core material.

doc · Posted: Thu May 01, 2008 3:26 am Post subject:

Warren, I too found the problem upon removal of the cockpit hatches for inspection of the suspected problem.