Wax is added at 2%
Thanks!
Yeah, I am planning on fairing all the little imperfections and the fiberglass repairs with West Systems epoxy and microlight filler, complete the longboarding of everything (bottoms), then gelcoat using the roller. Three to four coats. Then longboard the gelcoat again, then when fair, go at it with higher and higher grits. I ordered the waxless gelcoat along with styrene monomer, wax additive, etc. Should be here this weekend.
Did you thin your gelcoat at all?
What mohair roller/brand are you using? I know many rollers don't hold up to the styrene in the gelcoat and start falling apart.
It's been about 25 yrs since I was doing stuff like that and have forgotten at least half of what I knew. 🤣
PS. Also appears that you're sanding/gelcoating the whole hull with the amount of guidecoat that you have down. Is that true?
What was your reason for coating the whole hull? Lots of imperfections?
Thanks!
I didn’t thin the Gelcoat because I wanted to get as much on as I could with only 3 coats. It’s very time consuming because I had to mask off with each coat. Since I only did half a hull at a time it meant I had to do 12 coats for both hulls. The roller I picked up was at a paint store and was a reddish color, not sure what brand but was in a pack of 2 for about five dollars. Because you only have about 20 minutes to work it shouldn’t fall apart. The boat needed a complete replacement of Gelcoat and that’s why I decided to do the entire thing.
Thanks!
Yeah, in comparison, I'll likely 'just' have to gelcoat the bottoms of the F18 c2, and the bottoms and decks of the Mystere 6.0.
The Mystere is going to require a bunch of keel 'glassing and maybe even some deck removal/replacement.
I'll go to the local Sherwin Williams shop.... they may have some higher quality rollers that won't die in the middle of rolling. They're usually pretty reasonable in their disposables' prices.
I just want to register an alternate view - I haven't (yet) taken a shot at an entire hull refinishing (with either gelcote or paint), so I'm not speaking from experience. But the pros I've spoken with - and sailors who have owned and refinished a lot of cats - swear by paint rather than gelcote. Specifically, Tom at Aquarius uses Sherwin-Williams Genesis, which the manufacturer recommends for use on big trucks that see heavy duty. Tom says the stuff is absolutely bulletproof.
I had a lot of spider cracks and one major repair that I found when I was sanding the hull to prep it. I dont know if paint would have eliminated all the imperfections because it is a much thinner product. I still need to complete sanding with 800 and 1200 so I’ll be able to give a better estimate on how it turns out soon.
Just finished polishing one hull after sanding to 1200. I used 3M Perfect-it Machine Polish. First with a medium orange pad and then one time with a yellow softer pad. The hull looks almost brand new now! I will finish waxing with Collinite Heavy Duty "Fleetwax" formulated for marine and aeronautical. It has taken me about 1 month and here are a couple of things I learned.
1. 3 coats of Gelcoat is barely enough to sand off and get a nice finish. I sanded it starting with 220, then 320,400,800 and final at 1200. In retrospect I would go 220 then 400 and lightly use 800 to 1200. Ideally you need a couple more coats of gelcoat because you almost sand off 3 coats. Don't worry about extra weight to the boat.
2. Dry guide coat is a must. I used dry guide coat in between all sanding steps. In the beginning you can lay it on fairly dense. Dont try to get rid of it all on your first few sanding steps because you will sand a lot more gelcoat off then is needed. When you get to 800 & 1200 you only need a thin coat to see where you need to sand. The last 2 sanding steps are mainly to just get the scratches out from the 400 out.
3. Polishing with the 3M gets you to the mirror finish. I started out too fast. Take you time and don't use a lot of product. I used one orange pad and one yellow pad for each 1/2 of a hull. Don't let the pads gum up with polish.
Its a lot of work to re-gelcoat but the final product is going to last for a long time. The majority of the work is masking off the deck lids and trampoline track with each application
of gelcoat. I applied gelcoat 12 times. 3 coats to each half of each hull. I used Total Boat gelcoat and am happy with it. Don't mix up more then 24 ounces because its barely enough time before it goes off, something like 20 minutes.
Excellent posts!
One question... You didn't mention your sanding methods. How did you do your fairing and first couple of gelcoat sanding grits, with longboards or a powered DA (random orbital) sander?
I started sanding the hulls with a DA “Bosch” using 80 grit at the lowest speed.
The 80 grit was to prepare the hulls for Gelcoat. After Gelcoat application I started sanding with 220.
Finally done with polishing and waxing. Here is what you can expect from re-gel coating
hulls using a roll on method and a lot of elbow grease.
Nice!
I'm currently fairing my F18 C2 hulls with epoxy filler and looong-boarding with 80 and 120 grit, then checking the progress with a 48" aluminum straight-edge for any indications of bumps and hollows. Lots of little imperfections, especially around the forward half of the hulls, are receiving 'the cure.'
I just want to register an alternate view - I haven't (yet) taken a shot at an entire hull refinishing (with either gelcote or paint), so I'm not speaking from experience. But the pros I've spoken with - and sailors who have owned and refinished a lot of cats - swear by paint rather than gelcote. Specifically, Tom at Aquarius uses Sherwin-Williams Genesis, which the manufacturer recommends for use on big trucks that see heavy duty. Tom says the stuff is absolutely bulletproof.
Yes, I explored that avenue the other month, asking all the pertinent questions from the Sherwin Williams tech guy at the local store. ~$500 for 1.2 gal of that paint, plus the ~$100/gal required primer. One coat primer, at least two coats of polyurethane paint. Coverage would require at least two gallons of paint with HVLP spraying.
Sadly, my big air compressor that I've had for about 30 yrs took an irreparable dump the other day, and new compressors in the same higher air-volume class are pricey and of poor reliability these days, being all made in chinesium slave compounds.
So cost wise for hull coatings, painting would be at the very least $1100-1600, especially if considering removing most of the existing gelcoat and then fairing. In comparison, gelcoat costs ~$80/gal plus styrene monomer (if required), wax additive, rollers, sandpaper that I already have plenty of, would come out to around $200-300 with about equal amounts of elbow grease.
What would the weight penalty be for the gelcoat vs painting? Likely not much more than three pounds per hull once sanded and buffed. Plus, repair of a scratch would be super-easy and fast compared to repairing with paint, providing the equivalent visual quality.
AND.... gelcoating has far less immediate, harmful toxicity compared to the two-part polyurethane application. I've worked with a few of the 2-part polies on big boats, such as spraying Interlux Perfection and Akzo-Nobel coatings.... ya gotta be super-careful by fully covering-up your body and using a remote powered respirator.... yet more expense. I've seen some guys spraying without much protection... they're all long gone -- a very heavy price to pay. Rolling/tipping does work ok if the conditions are perfect (very dry air) and you're fast. But it's not a super-smooth finish.
So cost wise for hull coatings, painting would be at the very least $1100-1600,
@cat-scratch Wow! 😱
How much does Awlgrip cost these days? That was the go-to for a long time using a brush and the "roll and tip" method. Somewhere here there are pictures of some really nice complete paint jobs using that method.
So cost wise for hull coatings, painting would be at the very least $1100-1600,
@cat-scratch Wow! 😱
How much does Awlgrip cost these days? That was the go-to for a long time using a brush and the "roll and tip" method. Somewhere here there are pictures of some really nice complete paint jobs using that method.
Yeah, Awlgrip HDT ain't inexpensive, either, for the whole package of additives for one full application: $545 for a gallon of the white 'base,' $453 for a gallon of the 'curing solution,' and $45 for a quart of 'activator,' with mix ratios of 1:1:12.5% (Base:Curing Solution:Activator). Theoretically, that will cover roughly 538 sq ft per gallon per coat per the TDS. So, to fully paint a 20 ft cat (mystere 6.0) with tall-ish freeboard, let's say about 140 sq ft per hull, 330-350 sq ft total for both hulls to be on the safe side with around 75-80% spray efficiency. Let's be conservative and say 2(coats) x 350 = 700 sq ft hull/deck coverage for two coats. The full package of additives providing 2.125 gallons would provide roughly 1142 sq ft with 100% spray efficiency, or 857 sq ft with 75% spray efficiency. That's $1043 in topcoat paint alone, .
Yeah, we forgot the primer coat. We will need the Awlgrip 545 epoxy primer 'base' and 'converter.' One gallon of the base is $164, and one gallon of the converter is $154, mixed 1:1. The TDS indicates a Theoretical one-coat coverage of 473 sq ft / gallon at 100% spray efficiency. The TDS suggests THREE(!) coats, sanding the last coat, with a suggested DFT (dry film thickness) of 1.4 mil.
So we get about two gallons of epoxy primer should cover roughly 2 x 473 x 75% / 3(coats) = 236 sq ft of hull surface. Well, maybe we can be more efficient with a really good HVLP spray-gun setup and enough T0006 Spray Reducer ($26.50) to fully cover both hulls/decks.
So now we're at around $1043 + $164 + $154 + $26.50 = $1387.5 ... if we have quality equipment, and plenty of experience with spraying and providing adequate coverage. We might skimp on the epoxy primer and go two heavy-ish coats instead of three coats.
I would say that the Awlgrip HDT is (on paper) roughly the same expense as the Sherwin Williams 2-part that I was quoted, calculating coverage with both products' TDS sheets.
https://merrittsupply.com/product/awlgrip-hdt-polyurethane-topcoat-whites/
https://www.awlgrip.com/north-america/products
Awlgrip (Azko-Nobel) may have less expensive 2-part poly's available, but I didn't check, since this HDT is 'easily repairable,' which in my book is a big bonus worthy of a bit more expense with the ease of use down the road. Racing and high-usage cats will always need some touch-ups if appearances are important.
So yes... I think that I will stick with gelcoat for now.
If I wanted to have a really cool paint scheme.... maybe hot orange with black accents (maybe something like killer tiger stripes), then I would consider these paints.
😎
@cat-scratch Wow! 😱
How much does Awlgrip cost these days? That was the go-to for a long time using a brush and the "roll and tip" method. Somewhere here there are pictures of some really nice complete paint jobs using that method.
Yeah, I forgot that you were indicating rolling/tipping. Obviously, the paint would cover a bit more surface area with that method, but then there's the expense of the specialty rollers that (hopefully) won't shed and disintegrate and good brushes (not those cheap chippy things). I had some real fun rubbing out the roller particles in the dry paint on a 7-ton 34 ft sloop that I had roller/tipped.
Most rollers of the proper type for these paints are good, but there's typically at least one in batch of rollers that sheds. Oh the colorful sailor-speak will be heard throughout the marina.
Here's some helpful hints and such about re-gelcoating.
Well, I effed-up that calculation good!
...Theoretically, that will cover roughly 538 sq ft per gallon per coat per the TDS. So, to fully paint a 20 ft cat (mystere 6.0) with tall-ish freeboard, let's say about 140 sq ft per hull, 330-350 sq ft total for both hulls to be on the safe side with around 75-80% spray efficiency. Let's be conservative and say 2(coats) x 350 = 700 sq ft hull/deck coverage for two coats. The full package of additives providing 2.125 gallons would provide roughly 1142 sq ft with 100% spray efficiency, or 857 sq ft with 75% spray efficiency. That's $1043 in topcoat paint alone, .
Let's redo...
140 sq ft per hull, 240 sq ft total surface area.
Two coats would be approximately 480 sq ft total area. 2.125 gallons of mixed paint multiplied by 538 sq ft per gallon per coat provides us with 1143 sq ft with perfect coverage. With, say 80% spray efficiency coverage, 914 sq ft total, or 457 sq ft for half of that volume if you could purchase half-gallon volumes, which I don't see available. But still, you'd be short about 23 sq ft if the total hull areas are correct. certainly could get by with that volume with a smaller cat.
A quart of the base goes for $218. I don't see quart size for the curing solution.
Another less expensive option...
Awlcraft 3000 base is $308/gal, along with Awlcat #2 (G3010) $102 per quart) mixed 2:1, so you'd need two quarts of Awlcat, for a coverage of 741 sq ft / gal = 1111 sq ft total coverage. But the TDS indicates three coats. With light sanding in between each coat, so with 80% spray efficiency, 888 sq ft coverage, so that would work great. Would be ok for rolling/tipping. The TDS indicates that you might be able to get away without a primer if the substrate is sound, otherwise 545 epoxy primer is recommended.
So, without primer, we're looking at $512 in paint. That's a lot easier to swallow.
I did a Hobie 21 SE in Awlgrip, with epoxy primer and I could swear I did the whole thing with like 2 quarts of paint, with reducer separate. Used a cheap-o Harbor freight HVLP gun and it actually came out pretty great. Surprised. Held up very, very well. Spraying goes on way more economically and comes out better, IMO. And you need the epoxy primer as a tie coat. It was better than 90% efficient.
I did a Hobie 21 SE in Awlgrip, with epoxy primer and I could swear I did the whole thing with like 2 quarts of paint, with reducer separate. Used a cheap-o Harbor freight HVLP gun and it actually came out pretty great. Surprised. Held up very, very well. Spraying goes on way more economically and comes out better, IMO. And you need the epoxy primer as a tie coat. It was better than 90% efficient.
Excellent! At 90% TE (transfer efficiency), you must be very experienced at spraying. The best I've done and seen is around 75-80% with HVLP guns. Some gun providers' claims indicate up to 85% TE.
What Awlgrip formula? How many coats?
I painted a few big boats in the late 1990's and 2000's, some with spray, some with roll/tipping. The paint choices were much less than today's choices, but the paint of one of the boats (Luders 33') I did in 1999 that is now sitting in a pasture of mine still looks good, other than a bit of paint-chipping on the squared edges of the cove-line, possibly due to daily fiberglass expansion/contraction. That was Interlux Perfection 2-part. 1.25 gal did two coats on that boat. I think it was less than $150. But, the hardest thing that the boat has come in contact with were soft dock fenders. Didn't touch a lick of sand or rocky sand.
The paints were far less expensive then, too, even adjusting for inflation. But now we have oil prices at an all time high, gasoline is now $4.30 per gal in most places near me. Raises the costs of everything.
I saw the post from Cat Scratch re deck lids. So I already ground some of the lid to help bend it to the hull. The gap is about 1/8 in. on each side of the lid. I agree that the lid could leak around the screw on cap because the part was molded to remain flat. I saw a post from years ago for "This End Up" rebuild recommending the same fix. I think I'm going to try and fill the gaps with some 3M (4200) marine Adhesive sealant in white. I really don't want to permanently secure the lids to the hulls. If that doesn't
work at least I would still be able to remove them and come up with a better solution.
I painted the rear of the hulls and got new hardware to attach some parts...slowly getting there!
I decided to just go with marine grade silicone and put the deck lids on. The caps do screw into the lids but not the ideal fit. Going to see how well they are water tight. The front lids are more flat then the back ones. Another option is to make a gasket to fit between the lid and the hull. Something I may try another day!
I am looking for advice on some shrink wrap for my beam straps. I was able to purchase 4 new front beam straps but only 2 rear beam straps. I probably will reuse the best 2 old ones for the back beam. The 2 new rear beam straps came with shrink wrap around them and I want to install the same wrap on the rest of them. The new straps are 1 inch wide and the old ones are 15/16 inch wide. I saw this website for shrink wrap but am wondering what size to buy and how thick the product is. Any help is appreciated
.
I would NOT apply any form of coating or shrink wrap to any stainless steel or anodized aluminum. Stainless Steel requires oxygen to replenish it's protective finish. If (when) water intrudes between the steel and shrink wrap, it will begin to oxidize (rust) because there would be no oxygen. The best thing to do is to put a protective layer of galvanic isolation material (thin fiberglass, Tef-Gel, Duralac, thick packing tape) between the aluminum beam and the SS strap. That's it. Don't isolate any metal from access to oxygen if you like your metal to remain in good condition, especially if you sail in salty waters.
Interesting, I wonder why the 2 rear beam straps I bought brand new have it on them. When you said thick packing tape are you talking about the clear stuff? So don't wrap the beam strap but just put one piece between the beam and the strap? I probably will also buy a tube of Duralac as well.
Just got done cleaning the rear beam with this kit from "Everbright". It includes a cleaner and the coating. I used the cleaner, "ERW-XL" Rust Remover with a gray 3M scouring pad. It did a decent job of removing the white chalky build up and some small rust spots. I'm going to use it on the front beam and the mast as well. The 3M gray pads seem to clean it without any scratches.
Ya' just learn something new every day around this place!I would NOT apply any form of coating or shrink wrap to any stainless steel or anodized aluminum. Stainless Steel requires oxygen to replenish it's protective finish.
Interesting, I wonder why the 2 rear beam straps I bought brand new have it on them. When you said thick packing tape are you talking about the clear stuff? So don't wrap the beam strap but just put one piece between the beam and the strap?
Strange that NACRA would not understand about oxidative corrosion. Whatever.
Yes, only apply some sort of galvanic isolation material/goop between the two different metals. You could use what is known as 'Helicopter Tape', or the thick Gorilla Tape (clear) that I've purchased at Lowes/Home Depot.
https://gorillatough.com/product/crystal-clear-gorilla-tape
I've also used that tape on older hang gliders to 'fix' delaminating laminate leading edge sailcloth of the wings. It's tenacious and tough!
Sorry for the delay. I used Interlux Perfection, two part, reduced with 2333N, I think. I did do both hulls with one pack and reducer, but I did not paint the top-just the lower hulls, so that makes a huge difference. Problem was, it went on glass-beautiful then next morning was hazy when cured. Interlux technical was great-turns out I shot it too late in the day with the dew point increasing. I had to sand it to get tooth and respray starting like before noon because it needed several hours at a reducing dew point or low and level. Worked out fantastic second time. I think I had planned like 350 to 400 sq ft. I moved pretty quick and kept the overlap pretty low. That stuff, though is sort of noted for not being as friendly for touch ups, but can’t attest to that either way.
Just put some G10 into the slot I milled out with a multi-tool. This was the rudder that some how got ground down at the tip. Feathered it out and getting ready to lay some glass to build it back up. G10 was the perfect product to repair this kind of damage. After the glass I'm planning to re-gelcoat both rudders.
Looks like a split in the top of my rudder. It’s not something that can’t be fixed. I’m looking for any advice for a basic repair to hold for at least a season. I was thinking about sanding the slot a getting some epoxy in there. Then clamping it together. I really don’t want to demo the entire area to rebuild. Also wondering if anyone has a 5.2 rudder for sale that is in decent condition. Thanx