Hello everybody

I did not tie down my Inter and now I'm paying the price... Heavy wind blew her of the trailer and she took some damage on the right side hull. Here is a photo album showing the damages, I will update as the repairs go on: http://www.thebeachcats.c…ictures/?g2_itemId=91098

I was watching the West System video on youtube for idea, but was wondering if it is really nesseceary to get that invasive? http://www.youtube.com/watch?v=i97TlAdenv4

I was hoping to get some assurance on how to proceed before I cut the hull open. There are a few spots where the outer skin has turned white
Should I just grind the outer skin away and relaminate new skin? Or should I make a hole, a backing, new core and skin as per video?

In the most damaged area the core has allready been ground away, here I was wodering if it would be possible to laminate on the existing inner skin? From top to bottom the ground area is 10 cm/ 4 inches long



-CH-

--
Christian Kurkio
Nacra 500
Inter 20 (sold)
Pori, Finland, Europe
--

Hey Christian,

It's hard to tell from the photos the location of the damage, which look fairly common. First thing you might want to do is locate your bulkheads. I have a document/file that maps the location of all the bulkhead on the Inter 20. If you will PM me I will send it to you.

--
Philip
--

I fixed a similar ding on a 5.7, without cutting an access port. By cutting away the damaged material I ended up with an opening about 2". I used a piece of plastic juice jug, with 2 layers of wetted cloth. If you are really evil, use a laminated photo of your ex, or your boss,(if you really dislike them), there might be some satisfaction of having them cooped up in a dark, damp, sweaty stinky hull!
Fold it like a Taco shell & insert. The juice jug plastic will pop back to its original shape once inside the hull. A piece of nylon cord, or fishline was attached to the middle of the plastic backing. This could be pulled to force the patch against the inside of the hull til it sets up. You now have backing, add a layer of cloth to the outside, & you are ready for gelcoat. Be sure the outside layer finishes below the original gelcoat,(squeegee excess resin off) so as to leave 1 mm or so to blend the patch gelcoat even with the original.
Here is what I did. I should have taken more photos, but you get the idea.
It took longer to get the materials together, & string power out to my dock than the actual fix. I think I added 3 layers of cloth to the inside, (smallest against the hole, medium next, & a larger one against the plastic backing. You should be able to get a bent wire with some cloth inside, to wipe it down with acetone to ensure good adhesion.
The piece of juice jug will not adhere, it may end up falling loose in the hull once the banging around wears through the fishline, or whatever you used, but it only weighs a few grams, & won't rot or absorb water.
As Philp said, if you know where the bulkheads & stringers are it will make life easier, don't want to cut through those.
http://www.thebeachcats.c…ictures/?g2_itemId=77105



Edited by Edchris177 on Sep 23, 2012 - 11:01 AM.

--
Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
--

Christian,
Got the PM. File sent!

Edchris,
Don't know if you were speaking generically, but it might be helpful to others to know that the 20 doesn't have any stringers.

--
Philip
--

Yes it was a generic fix comment. I did not know the 20 is sans stringers, thanks for the correction, it may help Christian with his repair.

--
Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
--

ch_kurkio,
i am making the very same kind of repairs on an Inter20 myself right now. on the advice of a professional fiberglass boat repairman, i left the core material in place and did not cut large holes. he does this and uses the core material as the base for his resin & fiberglass mat & cloth build-up. on another boat i have, i cut out the damaged core material and i was sorry i did. it's not always necessary and i doubt if it's stronger than leaving the core attached.

what i have done is saturate the core material with resin, working it into any cracks. on top of that i started laying up cloth, then mat to build up thickness, then i finished with cloth which doesn't leave those fibers sticking out all over. after it hardened, it's as stiff and hard as the surrounding hull and sounds just the same when i tap on it with my fingers.

on those shallow scratches, it would be best to get in at least one layer of fiberglass cloth before you gelcoat.

that's my 2 cents!
BTW....love your Youtube videos!
j



Edited by arch on Sep 23, 2012 - 08:34 PM.

--
Aquacat 12 (sold)...'87 Nacra 5.8 (sold)...'03 Nacra Inter18 (sold)
Venture 15 (sold)....'89 Nacra 5.8 (sold)...'91 Nacra 5.8NA (sold)
'99 Nacra Inter20 (sold)
--

I did a small repair on my inter-18 without cutting access ports. Only about quarter sized, but I think you can go larger with his technique.

Cut your hole, chamfer, etc,

Create glass "backer" by laying 1 sheet on glass on wax paper. Create a few, just in case you drop/break lose one. It's cheap practice.
Weave dental floss into the backer in a few spots so you have a way to pull the backer up against the inside from the outside.
West System epoxy on the backer no additives. If you only wait about 12 hrs, it's very pliable and can be curved/rolled thru a smaller hole, experiment, YMMV.
"Glue" the backer in place with (pretty) thickened West System. Pull on your floss, tape the floss to hold your backer. wait 24 hrs. Cut/Sand off floss strands.
Water proof the hole with mildly thickened epoxy. Then go to town layering it up. And finish as needed.







Edited by nhanson on Sep 24, 2012 - 09:53 PM.

--
nacra inter-18
CNBP
--

Thank you everybody for your help, especially Philip for sending the info on bulkheads.

I uploaded more photos in the album showing how the repair is coming along.

I did cut a hole in the location where I had allready cut the material away, and made a backup piece. The backup was a 4 layer piece, laminated on the hull. Should have made it 2 or max 3 layers, the 4 layer piece was less than 1 mm thick and supringly stiff and durable.

In other areas the top skin was sanded away and new glass layers laminated and now sanded as well. I also put some gelcoat filler on some smaller scratches.

What material have you guys been using as filler, thickened epoxy maybe? Or do you use a separate filler?

Soon I need to get some topcoat too, though most say that it's no good on epoxy... I found these:

http://www.westsystem.com/ss/polyester-over-epoxy/

http://www.cruisersforum.…dhere-to-epoxy-5794.html


arch, nice that you liked the videos. The two latest videos were filmed a few days before the crash. Actually I have about 3 hours of video from that day, but tried to pick parts that might interest people. Also I have a problem in with my moviemaker not working, so I could add text and music, or put the videos together. The videos can be found here: http://www.youtube.com/re….0.0...1ac.1.hJvu2pcVJOw

-CH-

--
Christian Kurkio
Nacra 500
Inter 20 (sold)
Pori, Finland, Europe
--

ch,
for a filler material to fill in large dimples or depressions, i just used this 'paste' 100695 on my I20 hulls to fair them. it's a clear, slightly greenish color they call 'neutral' and they suggest adding color, in your case 'white' to match the hulls. this can be applied with a wide drywall trowel to span the repair. you don't want to get it any thicker than you need or outside the depression cause it remains kind of sticky and i've had trouble with it plugging up my sandpaper so it has to be trashed. (i know i mixed the hardener correctly.) they say you can sand it but i would just fill the depression and then top it with the gelcoat 105670, a one-step gelcoat that doesn't need a covering to cure.

spec sheet:
http://www.evercoat.com/imgs/pis/gelcoat.pdf

something else i've seen is adding a powder filler material to gelcoat to make a paste. do a search on gelcoat paste on the internet and you'll find different powders you can add to make it thicker.

i would stay away from bondo cause it can absorb moisture. and epoxy as a sub-layer may keep your gelcoat from curing. i found this to be the case on a daggerboard i repaired and wound up having to remove the gelcoat with acetone then completely dig out the epoxy. but some comments say it's ok over epoxy.

i've just found this all works well for me.
j

--
Aquacat 12 (sold)...'87 Nacra 5.8 (sold)...'03 Nacra Inter18 (sold)
Venture 15 (sold)....'89 Nacra 5.8 (sold)...'91 Nacra 5.8NA (sold)
'99 Nacra Inter20 (sold)
--

nhanson

I did a small repair on my inter-18 without cutting access ports. Only about quarter sized, but I think you can go larger with his technique.

Cut your hole, chamfer, etc,

Create glass "backer" by laying 1 sheet on glass on wax paper. Create a few, just in case you drop/break lose one. It's cheap practice.
Weave dental floss into the backer in a few spots so you have a way to pull the backer up against the inside from the outside.
West System epoxy on the backer no additives. If you only wait about 12 hrs, it's very pliable and can be curved/rolled thru a smaller hole, experiment, YMMV.
"Glue" the backer in place with (pretty) thickened West System. Pull on your floss, tape the floss to hold your backer. wait 24 hrs. Cut/Sand off floss strands.
Water proof the hole with mildly thickened epoxy. Then go to town layering it up. And finish as needed.



Edited by nhanson on Sep 24, 2012 - 09:53 PM.

We've had small holes like this at regattas and had to fix them quickly on the beach. We just use thickened epoxy carefully applied to just the hole with very little overlap to the edges. Let it harden and rasp off the excess, then sand flat with out hitting the surrounding area. Finish the area with 600 grit then 1200 grit, smooth as a baby's butt.

--
Philip
--

Quote

I have a document/file that maps the location of all the bulkhead on the Inter 20. If you will PM me I will send it to you.

mummp,
sent you a PM asking for this file. do you still have it?
thanks!
j

--
Aquacat 12 (sold)...'87 Nacra 5.8 (sold)...'03 Nacra Inter18 (sold)
Venture 15 (sold)....'89 Nacra 5.8 (sold)...'91 Nacra 5.8NA (sold)
'99 Nacra Inter20 (sold)
--

J,
Sending the file to your email address.

--
Philip
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