Started about here with my boat, fresh home from purchase:


Here's where we are today:



--
Chuck C
NACRA 500 Mk2
--

In case anyone is wondering:

1) Completely tear down cat; H21SE is actually scary-easy to tear down. Wash throoughly.
2) Rough sand with a Makita 7", variable speed sander/buffer with a soft, velcro backing pad (can't use a hard pad on fiberglass without gouging it).
3) Wipe down with solvent, draw the wear strip lines and tape off area to get epoxy; rough up with 80 grit, wipe with acetone then mix epoxy with UV clear hardener and add black pigment. Remove tape while epoxy is still "green". Ignore bugs in epoxy (they're "reinforcement").
4) wet/block sand after filing in little gouges, etc. with epoxy. Wet sand entire hulls.
5) Prime with Interlux 404 Epoxy Primekote, wet sand with 220 and...repeat.
- wet down grass and dirt; everything with a hose/water to contain dust and bugs (this works).
5) Light spray of the Interlux perfection; ignore bugs. Wet sand with 220
6) Final spray after wipe down following Interlux instructions on can.

Lessons learned -
1) You have to just stop and say "good enough is good enough". Could likely got show-car results if I wanted to fill, prime and repeat for another week, but it's getting warm. Need to sail and this is a 30 year old boat.
2) The H21SE's are built SOLID - I expected to uncover massive repairs/get surprises since it was painted previously over the original gray gel coat, but there wasn't. Just 1 good solid repair from what looks like roller damage sometime in the past. Nice.
3) Conflicting data sheets from Interlux; if spraying, you do not need, or want to thin past about 10%. 20%, as listed causes sagging. I only got one sag, though; the entire side of a hull...wet sand.
4) The NEW HF HVLP gun has a re-designed spray cap and internals. It's actually a GOOD gun (this is the model with a black internal nozzle). The old $12 purple gun, I basically would buy for primer jobs and once spraying epoxy primer would throw away after 2 sessions due to the mess. So, I used the new $12 gun to shoot the finish coat. Did as well as my DeVilbiss GFG-Plus gun, which is scary/impressive.
5) I used a plastic drywall sanding block that is padded for blocking the boat/wet sanding. That worked way better than I thought and prevented the paper from digging in, etc. And, was cheap.

--
Chuck C
NACRA 500 Mk2
--

Why all the prime, etc. efforts? Had to repair the wings, - permanently (as possible).

A little carbon fiber wrap, to make it go faster, of course:



Then, as a modification to the "jack-o-lantern" technique of opening a hull, I used fiberglass battens to back up the circle:



I drew an "X" across the circles I cut out so they would go back on perfectly and match the curve of the boat. This is what it looks like before sanding, etc.:


The pin stripping and goo was a nightmare to get off and ended up almost sanding every bit of old paint off the boat to make sure I got down to good material. That Primekote is good stuff, but a mess to work with. Once it starts kicking, you better be done cleaning, because you are.

--
Chuck C
NACRA 500 Mk2
--

Looking for some strip-down and primer shots, but I think I didn't get any. Got some more boat-hole marking, etc.:


--
Chuck C
NACRA 500 Mk2
--

Nice pictures Chuck, beautiful looking boat. On mine I had an access port on the top of the hull behind the rear crossbar to access the wing pockets for similar repair. Also worked well for rear transom repair.

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
--

Thanks -

Considered that, and may go that route in the future, if necessary, but in my final analysis I knew I could get the hulls opened, fixed and closed just as easy and cheaper. Plus, as it turned out I could make those repairs completely disappear. Turns out, the "pumpkin" method (credit: Hobie/Matt) worked out extremely well and super strong; I stress tested each repair (rap it lightly with a soft dead blow) and you can't even tell the repair is there. Also, I've done this repair twice, on the front two and they held up beautifully for a couple of seasons. Easy access, however has some appeal.

Biggest lesson - I'm getting a "little" out of shape; 4 days straight of wet sanding/blocking has left me achy...

--
Chuck C
NACRA 500 Mk2
--

WOW , great work Chuck. Now time to get the boat wet............

--
Bill 404 21SE
--

That is awesome!!! I am so thankful when I see these boats recovered!



Edited by bryandwayne on Mar 23, 2021 - 11:07 AM.

To anyone who's reluctant (like, are the bones of the boat worth it?) - I'd say that the effort DOES appear to be worth it. These hulls were really solid - I think my efforts will be rewarded with a reliable, relatively easy to sail cat. Handling on the beach is a bit tougher, but manageable. Will you get your money out of it? Only in fun, only in fun... However, considering that I've got less than $5k (probably closer to 4) total invested to-date, and fun over the course of 2 years, thus far, the return on investment appears solid. The renovation is much easier and less fussy than an old car, for example. And, you can walk away from it for a while, as long as it's sea-worthy by spring sailing... She goes back together this weekend.

--
Chuck C
NACRA 500 Mk2
--

Did you roll and tip Primekote or spray? Please describe your spray equipment for Interlux Perfection. I'm impressed you got it in 2-coats. This one?



Or this one:





Edited by tominpa on Mar 23, 2021 - 11:00 PM.

--
Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
--

Actually the first one. However, be warned you want the one with the black internal nozzle/spray tip. Some reason they completely redesigned the spray tip. It helped that the prime coat is bright white. It easily covered in two coats, but the first coat has to go on carefully-can't be too wet. Its the 67181, but looking at another old one I reserve for spraying Teflon, it appears the same, so I dunno. I do know you have to move pretty quick with it in full HVLP mode, like all HVLP guns.

Confession-I'm a bit of a tool whore and love quality stuff. The HF stuff is not my usual, but it worked really well. I have a 5 hp, 60 gallon shop compressor and 3/8" airlines so the gun is really flowing HVLP. You CAN set you air to 80psi at the hose and control down at the gun powered by a smaller compressor (to a point), but you loose the high flow and end up with more over spray. To do it again, I'd probably go back to my GFG, because I don't fiddle with settings as much, but wouldn't hesitate to shoot it again with the HF gun, not having the other. If you do smaller the Astro touch up gun is very high quality, if it's still available.

Oh, and make SURE you paint in the mid morning if you use Perfection without an accelerator. It'll flatten but quick in the evening if you don't have a good 5-6 hours good solid dry time before dew point starts dropping.

--
Chuck C
NACRA 500 Mk2
--

BTW, that second gun is probably better, from the looks of it, controls, etc.

--
Chuck C
NACRA 500 Mk2
--

Thanks for the additional details. I refinished my NACRA 5.7 with Primekote and Perfection Arctic White, but used a roll and tip method. Results are excellent unless you are examining it within a couple feet, but the Primekote took a LOT of sanding. I am going to be painting the 24' monohull this spring and already have materials ready. I wanted to spray the finish, and understand the first coat doesn't nearly cover or it will drip, but the second and subsequent coats go a bit heavier. My compressor is 25 gallon 2-stage rated at 6.41 cfm and 5.1 scfm @ 91 PSI, so I lack your air capacity. I'll give it a try and if it falls short, convert back to roll and tip.

GFG?

--
Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
--

You have enough compressor - I think the real consumption at max HVLP is like 6 SCFM@40 PSI

GFG plus is a Devilbiss gun:
https://www.autorefinishd…d-cups/plus-gravity.aspx

ACTUALLY, I can't stand it, so will be doing a couple of touch ups this weekend and will use the GFG gun as a comparison. It, however is an air HOG (10-12@40) and will put out a lot of paint real quick. You have to really pick up the pace with it compared to the HF gun. It's more of a full production gun, so we'll see.

Be warned - marine paint is in VERY short supply right now because of production problems, especially Interlux stuff. I just bought another quart and had to go through 3 vendors to find it in stock. Price is also going up. A quart of Perfection was $72; now at the same vendor it's $84 and $110 at West.



Edited by charlescarlis on Mar 24, 2021 - 01:07 PM.

--
Chuck C
NACRA 500 Mk2
--

I got the Interlux and Arctic White was not in stock, so I moved to Mediterranean White. Jamestown said mid-April for any product at all. I think my cost was $77.49/qt at Wholesale Marine. Got the Primekote for $107/gallon. I got the 2333 reducer in anticipation of roll and tip. Were you using the 2316? Thanks for taking time to answer.

--
Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
--

No problem with time - I mostly have been reduced to driving a desk all day... Yup, Wholesale marine for me also, same price. 2316 reducer for me, since I was spraying. I ended up buying a gallon of Epoxy Primekote, but dropped $120-ish. Another warning on that stuff - it DEFINITELY has a shelf life. I got some older from West and it scooped out about as thick as smooth peanut butter, but became more manageable when mixed - they swore up and down after calling somebody, that it was good and supposed to be like that. After a quart of that mess, I was doubtful. Then I dropped the coin for a gallon on-line and fresh it is more like the consistency of thick latex before being reduced. All of it kicked/set fine but that first quart kind of sucked to spray.

I tipped a little when I got sags on the first coat, but the 2316 I think evaporates too quickly. Tipping the sags on the first coat helped with sanding and prepping for the second. I guess I'll hit the boat with 800 grit, then 1200 then polish after touching up a dry spot and feathering that in to the rest. It'll be interesting to see how well this paint "repairs". Theoretically, it should be easy and blend perfectly into the existing paint.

Comparatively, I think this paint ends up a little more expensive than automotive single stage urethane. Should have been slightly cheaper, but now that I'm buying a third quart and bought more primer than expected, costs have tilted toward automotive. From what I can tell the only significant difference between the formulations is principally the lack of accelerator (isocyanate) in the mixing of the marine version, though they apparently have the option for that; just not readily available to buy. Guessing because of the health risks of the stuff. Oh, and I'm using a full face respirator with combination HEPA and OVA cartridges (purple and black). Need at least a half face respirator with purple/black or just black cartridges. You could likely mix outside in fresh air, but why?

--
Chuck C
NACRA 500 Mk2
--

I'm familiar with the isocyanate health risks and was an EPA manager (once upon a time) for NESHAPS (National Emission Standards for Hazardous Air Pollutants), and used to protect for Benzene, Vinyl Chloride, coke oven emissions, asbestos etc.) using supplied air, and various air-purifying cartridges. This stuff is bad, but hasn't killed me yet. I looked at my gallon of Primekote but can't find a date or any way of determining it's quality. It came from Jamestown as Discount Marine only had quarts.

--
Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
--

Chuck, looks great!

--
Bryan in Poplar Grove, IL
Supercat 17, unknown year. Future project
Hobie 16, 1977 - died a spectacular death https://youtu.be/Y7O22bp2MVA
Hobie 16, 1978 - current boat
--

The Primekote is obvious-it'll gel. But, it doesn't go bad, just gets harder to handle, mix and filter if spraying. All mine kicked just fine. You'll know pretty quick. I can't remember if I got my gallon from Jamestown, Boaters supply or what, but was mail ordered. Again, it was the very old quarts at the West store that had thickened.



Edited by charlescarlis on Mar 24, 2021 - 11:12 PM.

--
Chuck C
NACRA 500 Mk2
--

Chuck,
I just found your thread. I have owned 2 - 21SE's in years past. I so miss that platform. I am enjoying reading about your restore. Are you in DF? Where do you sail down there? Years ago, I use to work down there contracting my rich Uncle Sam. :)
Keep the updates coming.
Cheers,
Tom

Hey Tom - I'm down in the Houston-Galveston area. I guess Texas City Dike Yacht Club would be "home", but am looking forward to trailering the thing to some of the awesome lakes we have in the hill country and around Dallas now that it's really in a solid, reliable state.

For "quick sailing", I like Clear Lake, but you run out of real estate with the boat; it does have exit to the bay, which is nice. Then, on the right days Galveston beach front is actually really nice. When it starts to blow though, you can't beat the Texas City Dike; wind blows across the dike, flattened water on the sailing side, making a hot beam-reach. Gotta watch the ship wakes coming in every once in a while, but nice place to spend a day.

Everything renovated has been for strength, servicablility and reliability first, then appearance. I do like the platform, except the weight, which isn't an issue if launching at a ramp. Beach is where it gets to be more of a pain, but I'm working on that as well.

--
Chuck C
NACRA 500 Mk2
--