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Bottom Job #172809
03/25/09 09:01 AM
03/25/09 09:01 AM
Joined: May 2008
Posts: 40
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DangerMouse Offline OP
newbie
DangerMouse  Offline OP
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Joined: May 2008
Posts: 40
Hello again. Haven't been here for a while as I was extremely jealous that some were sailing while I was shoveling snow!

Anywho, getting ready for the upcoming season and need to repair a leak in my Nacra 5.0. The crack appears to be on the extreme bottom, and looks like a split where the sides of the hull meet. The entire bottom is a bit worn, and so I figured instead of repairing a spot here and there I would do the entire bottom.

My experience with fiberglass was about a week of instruction in an aviation maintenance class about 10 years ago. I have the general idea, using three'ish layers of fiberglass tape, each layer increasing in width, but am wondering how doing the entire bottom would change the procedure.

Should I do one long strip? Should I cut them up and do a 3 foot section at a time? Should I use a very slow hardening epoxy mix? Can I do one layer, let it dry, and then do a second? Or do I have to do all layers at once before they dry?

I tried doing a search but I probably wasn't using the right combo of search words.

Thanks ahead of time for the help.

The Nacra is upside down, taped off, ready for some lovin.
(kinky)


-- Have You Seen This? --
Re: Bottom Job [Re: DangerMouse] #172813
03/25/09 09:24 AM
03/25/09 09:24 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by DangerMouse
Hello again. Haven't been here for a while as I was extremely jealous that some were sailing while I was shoveling snow!

Anywho, getting ready for the upcoming season and need to repair a leak in my Nacra 5.0. The crack appears to be on the extreme bottom, and looks like a split where the sides of the hull meet. The entire bottom is a bit worn, and so I figured instead of repairing a spot here and there I would do the entire bottom.

My experience with fiberglass was about a week of instruction in an aviation maintenance class about 10 years ago. I have the general idea, using three'ish layers of fiberglass tape, each layer increasing in width, but am wondering how doing the entire bottom would change the procedure.

Should I do one long strip? Should I cut them up and do a 3 foot section at a time? Should I use a very slow hardening epoxy mix? Can I do one layer, let it dry, and then do a second? Or do I have to do all layers at once before they dry?

I tried doing a search but I probably wasn't using the right combo of search words.

Thanks ahead of time for the help.

The Nacra is upside down, taped off, ready for some lovin.
(kinky)



Do long one-piece strips down the hull. If doing it with temperatures above 75 degrees F, I would use 206 slow hardener (presuming you are using West Systems). If under 75 degrees F, the fast hardener will give you plenty of working time to wet down one full strip down the hull, apply the 2nd on top, wet down, apply the 3rd, and wet again. The idea is to get each layer down before the layer under it gets too far into the gel stage so the amine blush (the resin by-product of the curing process) can continue to rise through each layer ending at the outer surface and not between each surface where it can affect the bond. You can apply each layer to a wet layer with no problem. In all reality, though, wetting out each strip down the entire hull should go very quickly and cure time should not be much of a concern. Also note that direct sunlight will warm the resin a lot causing the cure to happen much more quickly.

I would also consider purchasing the fiberglass in a tape form...available from www.fiberglasssupply.com or www.uscomposites.com. You can get different widths that have knitted edges so you don't have to wrestle with all the loose fiberglass strings that invariably get all over everything...it's a neat convenient way to go.


Jake Kohl
Re: Bottom Job [Re: Jake] #172818
03/25/09 10:02 AM
03/25/09 10:02 AM
Joined: Jul 2007
Posts: 976
France
pepin Offline
old hand
pepin  Offline
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Joined: Jul 2007
Posts: 976
France
Do you really need 3 layers of fibreglass? If just a bit worn with gelcoat left you do not need to do that. If all the gel-coat is gone, it's a judgement call: are you down to the fibers or not?

What I've done on my nacra was to sand the bottom with coarse sandpaper to clean it up. It was then obvious the places that needed to be build up and the one just needing new gelcoat.

Near the transom, where a lot of material was removed by 20 years of use I used 4 layers of fiberglass/epoxy to rebuild the shape. I also used two layers in the back of the daggerboard well as it was showing signs of wear. In a couple of places I just put some epoxy with a roller to reseal some fiber properly.

I then re-sanded everything I added with the same coarse sandpaper to make a good clean rough surface and sprayed gelcoat on top of it. One pass with gel-coat thinned with acetone to get it to the point where the whole bottom is white, and then a second pass with gel-coat with wax add-on so it cures. And then a lot of sanding/buffing.

Re: Bottom Job [Re: pepin] #172824
03/25/09 10:42 AM
03/25/09 10:42 AM
Joined: May 2008
Posts: 40
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DangerMouse Offline OP
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DangerMouse  Offline OP
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Joined: May 2008
Posts: 40
Thanks for the quick replies guys. The bottom is worn down to the fiberglass. I don't know that I need to be doing any shaping, rather taking care of the holes and reinforcing the bottom at the same time. The place I sail the most has some nasty gritty sand at water level. There is one area that looks troubling. It looks like at some point the was quite a hole in the bottom, about the middle of the hull where the point starts flattening out. It looks like someone tried filling it, with what I don't know. It appears to have worked, but I'll feel more comfortable with some fiberglass over that.

I will be using West Systems, and will be doing this in my garage. The temp has been fluctuation through the 50's and 60's here lately.

The advice I've been given so far was given by a guy who used to do these types of repairs for a living in Hawaii. He is a Hobie guy, "warned" me against getting a Nacra because it wasn't as solid, and so he thought it might take 3 layers. He said to sand about 2 inches around the holes, down to glass with a vibe sander. Then use 3 layers, getting progressively wider. Said to use the West Systems stuff, and said to use peel ply on the top layer to save some sanding at the end. This was via PM at a different, general topic forum, without getting eyes on.

So one long strip it is. Do you use any particular type of throw away brushes? It's been so long... Do you impregnate the glass on both sides or can you lay it down and then put enough on that it soaks through?

How much time do you think the normal hardener would get me at the temperature stated above?

*I guess I've never seen what the shape should actually be on the 5.0 to tell if it needs reshaping or not. Any ideas?

Thanks again for the quick replies

Re: Bottom Job [Re: DangerMouse] #172832
03/25/09 11:43 AM
03/25/09 11:43 AM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by DangerMouse
Thanks for the quick replies guys. The bottom is worn down to the fiberglass. I don't know that I need to be doing any shaping, rather taking care of the holes and reinforcing the bottom at the same time. The place I sail the most has some nasty gritty sand at water level. There is one area that looks troubling. It looks like at some point the was quite a hole in the bottom, about the middle of the hull where the point starts flattening out. It looks like someone tried filling it, with what I don't know. It appears to have worked, but I'll feel more comfortable with some fiberglass over that.

I will be using West Systems, and will be doing this in my garage. The temp has been fluctuation through the 50's and 60's here lately.

The advice I've been given so far was given by a guy who used to do these types of repairs for a living in Hawaii. He is a Hobie guy, "warned" me against getting a Nacra because it wasn't as solid, and so he thought it might take 3 layers. He said to sand about 2 inches around the holes, down to glass with a vibe sander. Then use 3 layers, getting progressively wider. Said to use the West Systems stuff, and said to use peel ply on the top layer to save some sanding at the end. This was via PM at a different, general topic forum, without getting eyes on.

So one long strip it is. Do you use any particular type of throw away brushes? It's been so long... Do you impregnate the glass on both sides or can you lay it down and then put enough on that it soaks through?

How much time do you think the normal hardener would get me at the temperature stated above?

*I guess I've never seen what the shape should actually be on the 5.0 to tell if it needs reshaping or not. Any ideas?

Thanks again for the quick replies


Pepin is right, you probably don't need three layers. Two should be fine with the outermost sacrificing a little thickness for the finish sanding.

After repairing any imperfections, I would roughen up the hull with sandpaper where the new glass will go. Put masking tape 4 to 6 inches away from the edges of your final repair (use the painting stuff that has the folded plastic on it protects the whole hull easily). I would then brush on a thin but fully covered layer of epoxy on the hull as wide as the repair will be. Now lay the first layer of glass on the wet epoxy. then squeegie in enough epoxy to thuroughly wet that glass fully. I would use a comb roller (also available at www.uscomposites.com) to roll over the glass and work out any air bubbles. Now put the second strip of glass ontop of the other dry. I would now put in some more epoxy focusing on the outer edges of the top glass strip on the hull (leaving the center to soak up excess epoxy from the bottom layer) and roll again with the comb roller. wipe up any drips at this point and let it cure.

Once cured, I would scrub it down with a stiff bristle plastic brush and water to remove the amine blush. Then mix up a thick (almost peanut butter consistency) mixture of epoxy and microballons (phenolic or glass balloons - DO NOT USE colloidal silica as it will not sand) and I would squeegie this over the cured glass as a fairing compound. Use an old credit card, a plastic hotel room key (I collect these for composite work), or a store-bought squeegie for spreading out the filler. Let the filler cure and then sand to shape.


Jake Kohl
Re: Bottom Job [Re: Jake] #172863
03/25/09 03:32 PM
03/25/09 03:32 PM
Joined: May 2007
Posts: 149
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TurboCat Offline
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TurboCat  Offline
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Joined: May 2007
Posts: 149
Are you talking about the white filler on the Port hull? If so that is Marine-Tex that i put on there at the beach one day when the boat started leaking. It didnt look great but it definetely worked. The hole was not very big and i probably put on more than was needed. I wanted to be sure it was going to seal it up. Will text you in a minute about the paperwork.

Re: Bottom Job [Re: TurboCat] #172888
03/25/09 08:34 PM
03/25/09 08:34 PM
Joined: Jul 2007
Posts: 976
France
pepin Offline
old hand
pepin  Offline
old hand

Joined: Jul 2007
Posts: 976
France
Originally Posted by TurboCat
Are you talking about the white filler on the Port hull? If so that is Marine-Tex that i put on there at the beach one day when the boat started leaking.[...]
Well, to do a proper job I'd remove the temporary filler, expose the area and replace it with glass and epoxy. But it is just me, I don't like temporary repairs that stay on forever.

Re: Bottom Job [Re: TurboCat] #172925
03/26/09 10:29 AM
03/26/09 10:29 AM
Joined: May 2008
Posts: 40
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DangerMouse Offline OP
newbie
DangerMouse  Offline OP
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Joined: May 2008
Posts: 40
Hey hey! Good to hear from you. I don't remember if I mentioned in one of our conversations about the last day of last season. Put it over on it's side and when I climbed up on the hull to right it I heard a crack. At the end of the day (maybe 5 hours in the water) I went to drain her and the water just kept a coming and coming and coming. That Marine-Tex repair isn't the culprit. That's actually sturdy as can be.

Looking forward to the text!

Re: Bottom Job [Re: DangerMouse] #173126
03/28/09 08:44 AM
03/28/09 08:44 AM
Joined: Feb 2009
Posts: 41
Tampa, Fl
deepsees Offline
newbie
deepsees  Offline
newbie

Joined: Feb 2009
Posts: 41
Tampa, Fl
In all the replies in here... I did not see it mentioned that you need to turn the boat over to do this. It makes all the difference in the world than trying to do it otherwise.

Something else to consider is having to walk on the hull if you are flipped over. The glass will crack at the narrowest part of the hull if there is not enough cross section. Also, how much harder was used.

I used the thin cloth to start with and then put on two layers of heavy cloth cut in strips. Then when it hardened.. I shaped it back to a V with a belt sander. Now I do not worry about walking on the hull nor beaching.



Deepsees
Re: Bottom Job [Re: deepsees] #180313
05/30/09 02:54 PM
05/30/09 02:54 PM
Joined: May 2008
Posts: 40
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DangerMouse Offline OP
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DangerMouse  Offline OP
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Joined: May 2008
Posts: 40
So I'm finally getting to this project. Sanding the hull right now and as I'm taking the paint off I started wondering...how am I going to put it back on??

I don't have the equipment to spray it on. Can I roll it on? It doesn't have to look pretty, obviously, because it's a strip on the bottom about 1 inch on each side. Brush it on?

What do you guys think?

Re: Bottom Job [Re: DangerMouse] #180315
05/30/09 03:06 PM
05/30/09 03:06 PM
Joined: Jan 2009
Posts: 5,525
pgp Offline
Carpal Tunnel
pgp  Offline
Carpal Tunnel

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Posts: 5,525
Disposable roller.


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

Re: Bottom Job [Re: pgp] #180460
06/01/09 09:11 AM
06/01/09 09:11 AM
Joined: Jun 2001
Posts: 833
St. Louis, MO,
Mike Hill Offline
old hand
Mike Hill  Offline
old hand

Joined: Jun 2001
Posts: 833
St. Louis, MO,
Spray it!!!

Buy a disposable preval. They sell them at west marine to spray it on. That's all you need.



Mike Hill
N20 #1005
Re: Bottom Job [Re: Mike Hill] #180468
06/01/09 09:53 AM
06/01/09 09:53 AM
Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
Todd_Sails Offline
Carpal Tunnel
Todd_Sails  Offline
Carpal Tunnel

Joined: Jul 2001
Posts: 2,844
42.904444 N; 88.008586 W
You are going to use cat-wheels now, right?

When I started beach launching and sailing cats, we used to laugh at the few who had beach wheels.

Then, after getting newer/faster boats, and a bottom job or two, we started using cats-wheels.

Now, I try not to ever let the hulls touch anything hard.
Everyone I know now uses cat-wheels. There have been lots of threads, on inexpensive options to home build cat-wheels.

I now think, there should be no reason to do a wear and tear bottom job, if you use cat-wheels religiously.


F-18 Infusion
#626- SOLD it!

'Long Live the Legend of Chris Kyle'
Re: Bottom Job [Re: DangerMouse] #180724
06/03/09 06:41 AM
06/03/09 06:41 AM
Joined: Feb 2009
Posts: 41
Tampa, Fl
deepsees Offline
newbie
deepsees  Offline
newbie

Joined: Feb 2009
Posts: 41
Tampa, Fl
Rolling the paint will work... just not as smooth as spraying. But then again... if you are just painting the repair... it will be underwater for the most part. I highly recommend the purchase of a good orbital sander to take down the rough glass.... wear long sleeves or you will wish you had come bed time. Not to leave out the use of a breathing mask.


Deepsees
Re: Bottom Job [Re: deepsees] #180830
06/03/09 05:25 PM
06/03/09 05:25 PM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline
veteran
JeffS  Offline
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Joined: May 2006
Posts: 1,383
Kingston SE South Australia
If you use a 4 inch high density foam roller it will go on quite good. Mask where you dont want the paint, roll it then if you get a new soft bristle brush and gently tip it by starting at the bow down to the stern in one fluid motion it will come out like a spray job. If you have a look at the International paint website you'll find a video tutorial of how to do a whole boat.
regards


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
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