Skookum 47 Refit - San Francisco to Mexico

[Zach]

Minaret is right on target. He always gives great advice.

I'm a wooden boat builder that deals with epoxy construction and fairing...

Please don't do that to yourself while you still have the option of using gel coat for your primary fairing material. You'll save months of time, and can still awlgrip it once you hit 320 grit.

Most Awlgrip reps that I have dealt with are pretty good behind a spray gun. Some of them know what they are doing fairing.

Ask your awlgrip rep to show you how to push a long board, and how to sight down a batten. Have him hold one end and go through and mark and sand down a high spot. Go ahead and have some 3M dry guide coat on hand.

Have him show you how to run a DA, up and down. Long enough to burn through the first sandpaper. Most people don't change their paper often enough, and don't move their feet.

Ask him to show you how to screed on putty with a batten, instead of troweling with a plastic squeedgee. Don't listen if he talks about using a V-notch and sanding off the notches.

Gelcoat sands smoothly, and you can get an even coat over the entire surface with a paint brush or roller. That is much easier to get a smooth surface out of than starting with fairing putty and a long board. It's fairly self guiding... If you are sanding and see fiberglass, it's probably time to stop and check things with a batten.

Get a good 3/4 x 3/4 fir batten and a few lengths of straight edges... then figure out if your surfaces are fair before you start fairing and smoothing things out. I dare say that for the first 20 hours of a paint job... spend it getting to know your long board for half the time, and the other half of the time it should be with it leaned up against the boat and an eyeball pressed up against your batten to confirm that where your long board scratches aren't... are indeed low spots.

The long board is to check with a cross hatch scratch what your batten and eye confirm.

You can, of course putty the whole boat and sand down until you eventually find a fair one... but to do that you have to putty out further than the highest high spot and sand down without hitting it.

It takes a few hundred hours of staring at battens before people realize that fairing isn't about sanding through the grits. It's about carefully applying what needs to be where it isn't.

Mark where the batten does not touch with a faint pencil line, and then do not draw out side the lines with the putty. Folks start out mixing up a base ball size pile of putty and then spread it all over, which can work... but it works a lot better if you know where to put it.

Making things shiny is easy, but fair is a whole different ball of wax. All shiny takes is both burying the deepest scratches with enough stuff that you can sand out through the grits and not see them or hit any high spots.

Cheers,

Zach

[SF Bay Dude]

Thanks Zach and Minaret. So I'll entertain spraying a bit more, and I've got a wild and crazy question... I've got a really nice professional Graco airless sprayer. It can't quite pump elastomeric, but it has no problem with thick latex and has served me well. I could get some small finishing tips and blast it. Can I use that to shoot gelcoat? Sorry for the stupidity of the question, but this is all new to me. I'd worry that the batch would go off in the pump and wreck it, of which is among a list of many other reasons that would prevent one from taking this road.

[minaret]

Originally Posted by SF Bay Dude

Thanks Zach and Minaret. So I'll entertain spraying a bit more, and I've got a wild and crazy question... I've got a really nice professional Graco airless sprayer. It can't quite pump elastomeric, but it has no problem with thick latex and has served me well. I could get some small finishing tips and blast it. Can I use that to shoot gelcoat? Sorry for the stupidity of the question, but this is all new to me. I'd worry that the batch would go off in the pump and wreck it, of which is among a list of many other reasons that would prevent one from taking this road.

SFB Dude-do yourself a favor and read cpa's thread.

[SF Bay Dude]

Went through it Minaret. Definitely concentrated on the gelcoat parts. Thanks for the link. I feel like I am in a forum downward spiral. I think most importantly, for me, is to have a plan and see it through. Second guessing is a killer. That said, I am in a serious mulling stage right now. Time to run and do some work to forget about this for a while.

Cheers!

[minaret]

Originally Posted by SF Bay Dude

Went through it Minaret. Definitely concentrated on the gelcoat parts. Thanks for the link. I feel like I am in a forum downward spiral. I think most importantly, for me, is to have a plan and see it through. Second guessing is a killer. That said, I am in a serious mulling stage right now. Time to run and do some work to forget about this for a while.

Cheers!

Yep, it's tough. Big learning curve. Just take the time to work it out in your head before you do it IRL. There's no going back given the time and expense involved. Have fun!

[SF Bay Dude]

The best I can do to shootgelcoat is with this 30gal compressor and whatever gun you tell me to get. I'll also need a water/oil filter for the line, but those are pretty cheap and easy, non? I sourced a gelcoat dealer with gallon or 5 gallon buckets that I can pick up on my way down south.

In my heart of hearts this is the road I want to take. I understand spraying is worth it in the end. Trust me, I would spend a few extra hours masking (when I painted) just so I could spray. The finish is so much better. Also, I'd love to keep some left over gel from the batch as a touch up for down the road.

If you say this compressor can handle it, I will seriously think about altering course. Many thanks for you time and knowledge again!

[minaret]

Originally Posted by SF Bay Dude

The best I can do to shootgelcoat is with this 30gal compressor and whatever gun you tell me to get. I'll also need a water/oil filter for the line, but those are pretty cheap and easy, non? I sourced a gelcoat dealer with gallon or 5 gallon buckets that I can pick up on my way down south.

In my heart of hearts this is the road I want to take. I understand spraying is worth it in the end. Trust me, I would spend a few extra hours masking (when I painted) just so I could spray. The finish is so much better. Also, I'd love to keep some left over gel from the batch as a touch up for down the road.

If you say this compressor can handle it, I will seriously think about altering course. Many thanks for you time and knowledge again!

That's exactly the same model I used on my refit. Kept having issues with yard air. Every time I'd be in the middle of a big shoot, someone would fire up an air DA or two and I'd have to retune my gun. An hour later, they'd shut down, and all of a sudden the gun is cranked too high, resulting in instant hangers. So I picked up the cheap compressor. Wouldn't use one to paint a hull, but for stripes and decks it's fine, especially if you are shooting gel instead of paint. Only times I overheated it were long sanding sessions. It's a bit loud, but sufficient. Don't forget to check craigslist for a deal on something with more CFM, but that'll do it. I shot the vast majority of my gel with a cheap (DeVilbiss starting line) cup gun. You aren't trying to achieve a great finish when spraying gel. Use HVLP, dial down the tip pressure for less overspray, and hose it on. Less peel means less sanding, but you will have substantial peel regardless. The finish comes when you wet sand. Can't tell you about long term longevity, as mine died in the fire. But it'll do.


I think if you do some research and price out paint supplies, you will find that it is actually much cheaper for you to do gel than it is for paint. You will need a lot of material, and gel comes in cheap fivers. 545 costs a fortune. There's actually less sanding involved, in a narrower range of grits. It's only the wet sanding/polishing stage that is time consuming, takes more time than paint but far less materials expense. And a better product.

[SF Bay Dude]

Is this StartingLine DeVilbiss Kit the one you're talking about? Would you urge me to stay away from a cup gun? Seems like they are pretty simple and easy to clean.

I also found this gun and thought it might work well too. It draws 6-8.8CFM at 45-60psi compared to the DeVilbiss 13CFM and has an adjustable spray nozzle for dialing in a fan pattern, along with a 2 liter tank that's always upright. But the DeVibiss says 10psi cap pressure @ 13CFM, and I really don't know exactly how that translates or what that means in relation to how much air the compressor needs to provide. The 2 liter tank seems nice, although I am not sure if that is too much material to work at one time? From what I've read it seems that gelcoat starts to kick pretty fast.

Onto a mental gameplan to spray gelcoat. Here's what you wrote on the first page of this thread. Bear with me for the redundancy. Just want to make sure I've got this right.

Just take it down to bare glass, prep and degrease carefully, and roll/brush apply 4-5 coats of gel with wax in the last coat ONLY. Then very carefully sand that out nice and fair to 180 profile. Now you are ready to layout for finish gel. Spray apply, thinning with styrene monomer and MEK 50/50. Again, 3-4 coats (full wet coats), 1/2 hr between coats, catalyze 1%, wax in last coat only (surface seal). Full cure overnight, then guide coat and wet sand 800, 1000, then 3M ultrafine sponge, then polish with 3M Gelcoat compound. Guide coat again between 800 & 1000.

Here's my interpretation. Sound like it's close to the mark?...

I need to work in quart increments, spray small sections (like half the foredeck) at a time, and wait 30 minutes between each coat. Spray on 3 coats for the base with wax in the last coat, let it cure overnight, and sand that out to a 180 grit finish. I'll have to spray in the early hours of the morning because temperatures are still in the mid to upper 80's. Once the base coat is sanded and faired to 180, put on 2 or 3 more coats of gel, with the last coat having the wax added.

From your instructions it reads like I would put wax in the last coat of my base coat phase, along with the last coat of my finish. Is that correct?

Excuse my ignorance with gelcoat. Do the 3 base coats of gel need any additives beyond MEK and the wax on the last coat to help it fully cure? I thought I read somewhere it needed an anaerobic environment to fully cure?

As for material, I can get a gelcoat fiver thats manufactured by HK on the way south. I have no idea if there is a range of quality in gelcoat? Is HK good to use? Do you think I'll need more than 5 gallons? I can always start with 5 and see how it goes. Either way, yes, it's much cheaper than paint.

Next question is color. White is fine with me. I probably shouldn't even think about adding any pigments for my final coat, right? That question is laughable, but thought I would throw it out there anyway

Again, many thanks!

[minaret]

Originally Posted by SF Bay Dude

Is this StartingLine DeVilbiss Kit the one you're talking about? Would you urge me to stay away from a cup gun? Seems like they are pretty simple and easy to clean.

I also found this gun and thought it might work well too. It draws 6-8.8CFM at 45-60psi compared to the DeVilbiss 13CFM and has an adjustable spray nozzle for dialing in a fan pattern, along with a 2 liter tank that's always upright. But the DeVibiss says 10psi cap pressure @ 13CFM, and I really don't know exactly how that translates or what that means in relation to how much air the compressor needs to provide. The 2 liter tank seems nice, although I am not sure if that is too much material to work at one time? From what I've read it seems that gelcoat starts to kick pretty fast.

Onto a mental gameplan to spray gelcoat. Here's what you wrote on the first page of this thread. Bear with me for the redundancy. Just want to make sure I've got this right.



Here's my interpretation. Sound like it's close to the mark?...

I need to work in quart increments, spray small sections (like half the foredeck) at a time, and wait 30 minutes between each coat. Spray on 3 coats for the base with wax in the last coat, let it cure overnight, and sand that out to a 180 grit finish. I'll have to spray in the early hours of the morning because temperatures are still in the mid to upper 80's. Once the base coat is sanded and faired to 180, put on 2 or 3 more coats of gel, with the last coat having the wax added.

From your instructions it reads like I would put wax in the last coat of my base coat phase, along with the last coat of my finish. Is that correct?

Excuse my ignorance with gelcoat. Do the 3 base coats of gel need any additives beyond MEK and the wax on the last coat to help it fully cure? I thought I read somewhere it needed an anaerobic environment to fully cure?

As for material, I can get a gelcoat fiver thats manufactured by HK on the way south. I have no idea if there is a range of quality in gelcoat? Is HK good to use? Do you think I'll need more than 5 gallons? I can always start with 5 and see how it goes. Either way, yes, it's much cheaper than paint.

Next question is color. White is fine with me. I probably shouldn't even think about adding any pigments for my final coat, right? That question is laughable, but thought I would throw it out there anyway

Again, many thanks!

Will answer more questions later, but for now I'll just say that you will certainly need more than one fiver. Also, no two fivers will match, in any color. So I'd select the color you'd like (shade of white), and then get at least two fivers and box them together, ie pour them into a large container and mix thoroughly to provide a large amount of one color. Otherwise you will have trouble with this. Don't believe anyone who tells you they will match-they won't.

[SF Bay Dude]

Thank you Minaret. I learned about boxing the hard way from my painting days. A yellow house proved to be my ruin.

[SF Bay Dude]

That compressor isn't going to work. Just found out there are two 100 amp breakers in the yard, but they are shared… with the whole yard. With all the snowbirds heading down to work on boats, it's not gonna fly. That puts me into the corner of getting a big generator, which I don't really want to buy and haul down there.

Spoke with the Awlgrip rep - he emailed me on Sunday to set up a call on Tuesday - and recommended I use Awlgrip Hullguard Extra Epoxy Primer (based on paint as the final topcoat). Put that on over the bare glass that I grind/sand down to, then use 545 to prime, and then finish topcoat with Awlgrip.

I was also thinking that I could use gelcoat as a nice primer/fairing surface. It sands pretty easily and I can lay it on fairly thick. It's cheaper than paint. So maybe that's something I'll look into.

I suspect my progress is going to be slow (slower than I hoped, as it always is), and I reckon I'll tackle the bow area first to get a handle on things. No hatches or crazy angles. Just a lot of flat that will be all non-skid. I plan on hiding more than a few sins underneath the grit.

I have a nice pile of tools and sandpaper staged in my home office. Looking forward to getting dirty.

[SF Bay Dude]

Eve of departure day! Wait, that's confusing… I leave tomorrow. It kind of feels like getting ready to cast lines from the dock. Van is packed to the gills, but hiding everything pretty well. I've got a ton of awlgrip products stashed in cubbies with motor oil and "regular" stuff in front of it. Lots of tools and other gear in the roof box.



Decided to go the Awlgrip route. In the end, shooting gel seemed the more detail laded task. I am familiar with paint, and can't wait to rock my rolling and tipping skills (read sarcasm).

I'll start grinding with 24 or 36 discs to remove the industrial sand that previous owner put down, then switch over to sandpaper. I just hope I have enough to get the job (or the section I am tackling) done! 150 discs of 40 grit to start, then 50 discs of 50, 60, 80, 120, etc. Plus I've got a few 20 yards rolls of 80, 100, 120 grit in 4.5 inch and 2.75 inch for the boards. I can already feel the burn.

Doing a grocery run in the morning to stock my fridge and cupboards. Packed the heritage pork chops, bacon, and sausage from our 1/2 hog share, honey from my hives, and eggs from our chickens. I should last at least a few days

Now for the 3 day drive

!Viva la Mexico!

[minaret]

Originally Posted by SF Bay Dude

Eve of departure day! Wait, that's confusing… I leave tomorrow. It kind of feels like getting ready to cast lines from the dock. Van is packed to the gills, but hiding everything pretty well. I've got a ton of awlgrip products stashed in cubbies with motor oil and "regular" stuff in front of it. Lots of tools and other gear in the roof box.



Decided to go the Awlgrip route. In the end, shooting gel seemed the more detail laded task. I am familiar with paint, and can't wait to rock my rolling and tipping skills (read sarcasm).

I'll start grinding with 24 or 36 discs to remove the industrial sand that previous owner put down, then switch over to sandpaper. I just hope I have enough to get the job (or the section I am tackling) done! 150 discs of 40 grit to start, then 50 discs of 50, 60, 80, 120, etc. Plus I've got a few 20 yards rolls of 80, 100, 120 grit in 4.5 inch and 2.75 inch for the boards. I can already feel the burn.

Doing a grocery run in the morning to stock my fridge and cupboards. Packed the heritage pork chops, bacon, and sausage from our 1/2 hog share, honey from my hives, and eggs from our chickens. I should last at least a few days

Now for the 3 day drive

!Viva la Mexico!

Good luck!

[SF Bay Dude]

After 5 days of driving over 2700 miles roundtrip and 23 straight days of grinding, vacuuming, sanding, sweating, masking and finally painting, I finished most of what I had hoped to accomplish. That included taking the entire gelcoat off of the decks, cabin house top and sides, walkways, and the cockpit, then re-coating everything with paint and non-skid.

The first day of actual work I tried my 5 inch angle grinder with a 16 grit disc, and it just wasn't doing any damage to the aggressive coating of LPU and sand that the PO had put down. I was pretty damn deflated. So on a whim and with some luck (as in there being a Home Depot in Guaymas) I bought a diamond studded masonry grinding wheel. The first pass relieved all my worry. That thing took material off like a hot knife through butter. So much that I had to be really careful not to cut into the fiberglass.







So I suited up with my Tyvek, strapped my full mask and ear muffs on, and went at it. Wore the first one out in 2 days. Another full day and I was done the major grinding. I then progressed to 40 grit down to 80 as I worked my way around the whole boat a few times. My back was tired and I was sporting some pretty good crab hands from gripping the sander, but it was all good, as I knew the endgame.







I used Hullguard Extra for a first base coat once things were sanding up to my liking. I then used Quickfair for filling in places where the grinding wheel got away from me. It didn't happen all that ofter, and seemed like it was always at the end of the day. I liked the Quickfair product. It was easily mixed and always set up correctly for me (except once when I tried something "new"). I found it easy to sand, but it did have a tendency to gum up on the pads. I just took them off and gave them a few knocks to clear them off.











After that I primed with 2 part awlgrip primer. I wish I had brought down another 2 gallons. Each complete coating used up one gallon. I thought I was going to get away with more. I used the 2nd coat to broadcast sand on and have it stick to the primer. I was originally going to use a mix of Interlux's micro-spheres and awlgrip's coarse griptex, but I didn't think I had enough material nor paint (it really sucks up the paint) for an entire coating. As luck would have it, another cruiser had some pre-washed sand in 40 or 60 grit (can't remember what it was) that he was giving away, and I decided to use that in combination (or at least I thought…)





I would have liked to have had another coat or 2 of primer over the sand to hide the color bleed through, but I'll save that for another day. I got 2 coats of finish white awlgrip down to seal the deal.

I mocked up a test patch (days before) that had a crucial difference that I didn't include in the final layup. And that is, when I did the broadcast method of sand, I over-coated it with 3 coats of paint and the little spheres that Awlgrip and Interlux sell. That helped fill in the gaps of the sand and take the teeth out of the grit. But once I got rolling with paint on the decks, I knew I was going to be short, but didn't have much of a choice to stop.

Right before I left, I sanded out a test patch with some 40 grit, and I knocked it down fast. I know it sounds crazy, but next time I am down, I will sand it all down again and get a the proper layup of sand and griptex that I want. It's not something I want to do, but once she's back in the States, there's no way I can do the work up here.





I'll also have to finish out the cabin house sides, rails, raised edges, and other areas of of gelcoat that are intact and not affected by the flub at the factory. But that can be done in due time as well.

All in all, it's so good to be back home with clean running water and toilets that allow toilet paper. I will not miss the wolf spider that watched me shower, nor the trickle of warm water that emanated from the saddest shower I have seen in a while.

Cheers!

[minaret]

Congrats! Good job diving in.