Re-gelcoating my deck: Project thread

[scherzoja]

Originally Posted by Suijin

...
I'm going to end up with a couple of dozen 1/4" bolt holes in the deck that need to be filled. Plan was mat patch underneath, stuff mat and resin in the hole, then patch and fair on top. I see you guys have been talking about this in the last few posts. I'm listening.

....

Suijin,

Referring to your question in post #39 about how to patch the dozens of holes.

I slapped piece of poly/mat on the underside to plug the hole, then I used polyester resin mixed with milled fiber until I got viscosity I wanted. Sometimes thick, sometimes not very thick.

Used a syringe to fill from bottom up to chase out air.

For larger holes, like the water fills (2" to 3" dia holes), where I am just filling the hole, I used combination of 1/4 fibers, 1208, and poly resin thickend with milled fiber (powder stuff)

Patch underneath, throw in some 1/4 fiber to fill the uneven bottom of the hole.

Then layer in some 1208. Couldn't get the ends to stuff up under de-cored area, so I just mashed in some 1/4" fiber and resin or thickened resin. I finished it off with some not-so-thick resin/milled fiber (powder).

Attached is crude diagram of the water deck fill patch.

For areas where fittings are, used thick epoxy to fill the de-cored area and was careful to make sure any deck I removed was no larger than the footprint of the hardware.

So, I use epoxy where hardware sits on top, poly/fiber where it's just a patch job that will get gelcoat.

I found that most of the patches are in the non-skid, which will very likely not be gelcoat. Very few patches are in the smooth area and those are mostly small holes where I had no reservations about using just polyester resin.

The new holes for water fills will be carefully cut out, de-cored, and epoxy filled, but no epoxy will be in contact with new poly or exposed to UV rays.

[Suijin]

All the holes that I'm filling in, completely, are small. Either #10 screw holes or 1/4" bolt holes, so the milled fibre approach will do nicely.

I'm regelcoating the WHOLE deck, even though probably 80% of it will end up with Awlgrip non-skid on top. It's just easier overall, and there is a good chance that when the molded in nonskid gets ground off I'm going to be exposing the laminate anyway. Just buy 10 gals of gelcoat and go to town, then fair the whole bugger. At least I won't have to polish the non-skid areas.

Since I'm regelcoating, I'm not going to use epoxy for the wet spot repair. It's going to be Poly so I can put gel down on top of it.

And yes, pretty much every bolt and screw hole is going to get the epoxy fill and redrill treatment. That's a #$%@-ton of holes...about 300 (150 for all the stanchions and pulpits alone) all told I would guess. Fortunately, anything larger than a bolt hole, the core was sealed when the boat was built. Valiant did an excellent job in that respect.

[Suijin]

So I figured I would open up the wet spot today to give it time to dry out while I move forward with other things.

Geared up and marked the patient:



The small drill was to pre-drill the pilot hole, to prevent breaking my wrists if I used the one on the 6" hole saw.

Top skin cut:



Took some doing to pry up the skin. "Hmm." I thought. "Must not be as bad as I thought." Then the shocker:



Pretty much fine. Didn't even feel damp. There was one small darkened spot, but not worth cutting up the deck for. I'm very surprised, as I sampled the deck all over and this was the only spot that read anything other than solid green, and the needle was almost pegged in the red in the center of this. There's no backing plate either, no metal nearby, it's all homogeneous deck underneath. HUNH. Oh well. If I had not cut it out I would have been wondering, endlessly, if I should have.

Moved on to doing some tests on the cracked gelcoat:



Did about a dozen of these, sampling pretty much every area where there are cracks. None of them went into the laminate under the gel. Definitely not stress cracks. I'm pretty sure it's just thick gel that absorbed water and then cracked in winter.

This also revealed that the gel is THICK over most of the boat. We're talking 1/16" and up. That's like 30 mils. Not only does that give me lots of material to work with in terms of refinishing, if I sprayed new gel on top of this I'd have crazy thick gel.

So I'm thinking about just repairing all the cracks and then refinishing the existing gel instead of spraying new. I have to repair and fair all the cracks anyway. The issue will be color matching, which I'm actually pretty good at using the saran wrap method. It would save me a HUGE amount of work.

Went at a section with 800 wet, then 1200 wet sponges, and I got to good gel pretty quickly. No pinholes, nice and smooth, and not a lot of material removed. Yeah, I think this is the way to go.



That said, I'm still going to grind off all the molded-in nonskid and do paint nonskid. Will still need to spray new gel on top of that if I hit laminate, which I expect I will, but I won't have to labor to get it polished. Just take off the orange peel, run over it with 220 (?) and start painting. Part of the reason for this is wanting to reconfigure the nonskid pattern on the deck to better follow hardware changes etc.

Finally got my propane locker out the other day. Another chore, another task for the car jack to pop it out. The the caulk clean up. I have some acrylic scrapers I made from an old fishtank that are perfect for this...they strip off caulk without scratching the gel:





I have a fistful of them and when they get dull a quick trip to the belt sander puts a new edge on them.

[jhulmer]

Originally Posted by Suijin

Anyone have a comment on the above and my options? I don't want to open up the deck for a small wet spot if either it will eventually dry out on its own (moisture eventually absorbed/dissapated into surrounding wood) or there are other less invasive options for remediation. Could use some feedback from those who are the familiar with the longer term implications of small spots like this.

Suijin
fyi - I am still following with great interest, so thank for the post and pics.

I ran into the same problem of moister in my deck where the teak deck screws leaked into the core. The core was only damp in most places and wet in a few. I knew I had time in the shed to let it dry naturally so I opened the holes to 3/8” and dug out as much coring as I could and ran fans over the top constantly. This took about six months but it is dry as a bone now.

[minaret]

This is why we always confirm the meters results with a little drilling, from below if possible.

Often when I see this, it's the result of a glass patch with an accelerant on the underside of the deck. Cobalt is a common accelerant and will cause a laminate to read wet. The red dye in your laminate may be just the usual MEKP dye or it could be an accelerant, the most common of which are red or blue. Is your laminate red everywhere?


I would definitely suggest more thorough exploratory grinding on those cracks. They are severe and when I blow up your pic it's clear to me that the one you have ground to bare glass continues into the laminate. Grind a little wider to bare glass and wipe with acetone. Inspect carefully for crack in the laminate while it's wet with tone. If you gel coat over cracks in the layup they will 100% come back, and in pretty short order.

That is some super thick gel. Glad a restoration will work for you!



Sorry I'm not on top of this daily, on vacation in Cali. It seems like you've got a good handle on it though! Keep at it....

[Suijin]

Minaret, I'm going to go back and check with a magnifying glass and the acetone wipe. These were just preliminary, exploratory grinds, and they are all going to get dished out and sloped. That said, I've inspected pretty closely, and can't see glass cracks in most of the problem areas. Where they are, they're pretty obvious

What I'm finding is that the cracking is where the gelcoat is very thick, around the risers for the hatches and along a few vertical surfaces meeting horizontal surfaces. As the gelcoat slopes away from the turn, or the riser, and thins, the crack disappears. It appears directly proportional to gelcoat thickness. The other place where it's prevalent is the decks aft by the combings, where ice sits on the deck if it snows and the boat is not covered. I won't be surprised if I find glass cracks back there.

The underside of the laminate is red throughout. The top of the laminate is grey. My understanding is that each schedule was colored differently to facilitate good layup:

"Isophthalic resin used throughout the entire lay up of hull, deck, and all other fiberglass components. The resin is hand-batched and catalyzed in one gallon increments. The catalyst/resin mixture is dyed to achieve the proper wet-out technique."

Anyway, I'm in the seventh circle of hell right now. This grinding is a major bitch, with huge quantities of dust. And this tent gets hot by noon, and it's only April. Add the Tyvek, hood, mask and gloves and I'm a sweaty pig before lunch. Gotta get this done before it warms up further or this is going to be extremely unpleasant.





The 8" soft pad did not fit on any of the mud hogs here at the yard so I've been using my Hitachi grinder/polisher, keeping it flat or a 2 degree tilt and keeping it moving. The issue I ran into is that the deck is actually fairly uneven, which you'd never notice unless you were doing what I'm doing, particularly with the molded non-skid. On top of that, the gelcoat thickness varies. So I have areas where I'm down to bare glass just to get the texture off, and other areas where I have the texture off but there are dips where there is still texture. I'm clearly going to need to fair some low spots. What I'm wondering about now is how to effectively identify those areas. The light is so even in this tent that it's impossible to use it to see what's what. Thinking about making a few battens, or just lengths of lathe, and running them across...or coming back at night with a flashlight and raking it over the surface. Or both. Fortunately, for whatever reason, this is primarily clustered around the forward part of the coach roof and the forward port deck.

The edges of the nonskid are a bit of a bitch, since it's raised. I want to preserve that profile, so have to be very careful grinding/sanding that I don't get a wavy edge. Will go back and hand finish with a block but with the grinder it's easy to slip and make work for yourself so have stayed away from the edges. Speaking of slipping with the grinder:



Just an occupational hazard. I've used this grinder a lot and so am familiar with exactly how much skin it can remove in a nano-second, but I'm always surprised when this happens. Literally touched me for a fraction of a second at lowest RPM and through the suit, the shorts, and into my skin. Whew!

[minaret]

Yes! Seventh circle is appropriate. But this is how you will find and repair all flaws as part of the process. No substitute for doing it yourself! Except maybe hiring someone like me who is completely OCD, but most of us have that beat out of us by this process pretty early.


Get a small cheap shop vac with a skinny hose. Buy extra length of 1" extra flexy vac hose on ebay. Hook up vac hose to exhaust on vac so it blows not sucks. Now cut a hole in your Tyvek at the small of your back. Tape that exhaust hose to the hole with duct tape very thoroughly. Voila! Air conditioned Tyvek suit. Put the vac outside in the shade where it's sucking the coolest possible air. Be sure to use a brand new vac that's never had glass dust in it! Oh, and just remove all filters and bags for more flow. You can even put a bag of ice in it if it's really bad. Make your tape go all the way around like a belt so it doesn't rip the tyvek.


I always stick a thermometer on the wall of a tent/shed for catalyst ratios. 120F is not an uncommon reading even here in the PNW. I've been saying for years that we need to sell business as a fat camp; this way the employees/workers would pay us as well as the clients!



Careful with that grinder! I've certainly got my fair share of grinder bites; it happens. Just keep that full face on, I've trashed a few face plates kicking a grinder back right into my face with 16 grit, probably wouldn't have a face anymore without good personal safety gear habits!

[minaret]

Oh, and don't make that deck too fair. Griptex will hide the unfairness just fine, especially if you go full flat on the paint. You didn't notice it before, neither will anyone else. It's easy to get carried away and over do it. Fairing takes forever, and if you think you're in the seventh circle now, you will have graduated to the ninth circle when it gets really hot and you pull out a long board/misery board!

[minaret]

Also think about setting up some big lights and starting before dawn. I do this often on a big grind. I also often have big squirrel cage fans (nice quiet low draw ones) set up both to circulate air in the tent and with one blowing right on me as I grind. This makes clean up a bitch since it blows the dust everywhere but it's better than passing out!

[minaret]

This Neiko is the cheapest mud hog you can buy. You might consider picking one up real quick IF you have a lot of air handy. For decks it is often a HUGE time saver. It is good at the stage you are currently in, ie removing material without making the deck unfair. But it will also earn it's keep when you start fairing the deck. IMHO only the edges and waterways need to be really fair. Many a deck I've done only "machine fair", which means air longboards and a mud hog with hand work at edges and waterways only. This is more than acceptable for most people/boats.

At $80 or so this tool will pay for itself if it saves you a couple of hours. It will save you WAY more than that! If you have the air....



https://www.amazon.com/Neiko-30075A-...orbital+sander

[minaret]

If you tape a vac hose to your suit hang it on an overhead loop like you would run an air line for spraying paint so it doesn't get hung up. Have fun and good luck!

[Suijin]

Thanks Minaret.

The vac blowing into the suit sounds like a good idea...it might well come to that. I'll definitely keep it in mind. I'm definitely getting there at first light on warm days until this is done.

Fortunately I'm mostly done with the major grinding so no need for the mud hog. Have already bought a fistful of tools for this project as it is. Including that 12v. Milwaukee polisher/sander. OMG that thing is great. It's a fiend with a roloc disk, have not gotten to the polishing part but can already see how it's going to be indispensable.

BUT, it came with a 2" roloc pad on a mandrel, and I have zillion 1" discs that I rely on...and I can't find a 1" mandrel for the damn thing as it is (what appears to be) funky 10mm .8 thread to screw into the tool. I can't find any screw-in mandrels, wtf. Will have to employ my Google-** a bit harder or MacGyver a solution.

It occurred to me that I should not go crazy on the fairing. In truth, it's going to be flatter than it was given the grinding. I've been very careful. So I'll probably give it a once over and hit any dings and obvious low spots and call it done. I'm going to do a bit more in the cockpit as there were a couple of low spots where the water sat which always bugged the hell out of me. It's going to drain properly when I'm done if it kills me.

Did more detail grinding of the edges of the non-skid with the orbital today and that's going pretty quick. Also chased out a bunch more cracks. Wiped a few with acetone and inspected as closely as I could and could not see any cracks, but am searching for my magnifying glass to double check. There are a few with cracks, that I saw earlier, and the cracks are pretty obvious...a line that does not go away, so I think I'm seeing it right.

There had been an existing bad repair of cracks in the cockpit that I ground out today. OMG grinding them out, the repairs were worse than I thought. Ground out glass that they had just filled with poorly-matched gel. No wonder it cracked again, it was so thick.

I'm about to order some pigments for color matching and I stumbled across a post that you wrote a few years about about color matching. You talked through the mylar trick and said you did not know why it works but it does. I'll tell you why it works, in case it never hit you...

Polished gelcoat and wet uncured gelcoat have different specular reflectivity, with the polished gel being lower. Sandwiching them both under mylar, the polished gel with some spit on it, gives them both the same specular reflectivity.

The spectral reflectivity of an object has a direct effect on it's perceived hue and value. If it's lower, diffusing more like and reflecting less, it's going to scatter some wavelengths and reflect others, changing it's apparent hue. If it's more diffuse it's also going to appear darker because it's reflecting less light. Your solution fixes that.

I ordered some mylar, lol.

Chain plates are made. New traveller is done. New stainless handrails are almost done. They are works of art. Turns out Dan the fabricator worked for Palmer Johnson for a bunch of years. I'm feeling a bit super-yachty. So now I just have to get the deck done so I can start putting the poor girl back together.

Reminds me I need to inventory fasteners and start ordering new ones. It's gonna be expensive. I'm pretty sure at this point that I could have parted the boat out and gotten more than it's market value. As I've stripped stuff off I've been pricing it, just to toy with replacing stuff. Dear god, the Perko hawsepipe inserts are $100 each, and I have eight of them. Ridiculous.

[minaret]

Originally Posted by Suijin

Thanks Minaret.

The vac blowing into the suit sounds like a good idea...it might well come to that. I'll definitely keep it in mind. I'm definitely getting there at first light on warm days until this is done.



Lol, lets hope it doesn't come to that for you! Coming in early does help a lot, most people can't grind for more than about six hours anyway.




Fortunately I'm mostly done with the major grinding so no need for the mud hog. Have already bought a fistful of tools for this project as it is. Including that 12v. Milwaukee polisher/sander. OMG that thing is great. It's a fiend with a roloc disk, have not gotten to the polishing part but can already see how it's going to be indispensable.



Yeah, that little sucker rocks! So nice to have when away from the yard, especially.






BUT, it came with a 2" roloc pad on a mandrel, and I have zillion 1" discs that I rely on...and I can't find a 1" mandrel for the damn thing as it is (what appears to be) funky 10mm .8 thread to screw into the tool. I can't find any screw-in mandrels, wtf. Will have to employ my Google-** a bit harder or MacGyver a solution.



Yeah I had the same problem. But I use so much more 2"
than 1" that it hasn't really bothered me, I just chuck a 1" into something else when I need one. Lemme know if you find one!




It occurred to me that I should not go crazy on the fairing. In truth, it's going to be flatter than it was given the grinding. I've been very careful. So I'll probably give it a once over and hit any dings and obvious low spots and call it done. I'm going to do a bit more in the cockpit as there were a couple of low spots where the water sat which always bugged the hell out of me. It's going to drain properly when I'm done if it kills me.



Yep, take any time you may have planned to spend fairing the nonskid areas of the deck and spend it elsewhere, for the most part,
and you won't regret it. Put your time where it will show!





Did more detail grinding of the edges of the non-skid with the orbital today and that's going pretty quick. Also chased out a bunch more cracks. Wiped a few with acetone and inspected as closely as I could and could not see any cracks, but am searching for my magnifying glass to double check. There are a few with cracks, that I saw earlier, and the cracks are pretty obvious...a line that does not go away, so I think I'm seeing it right.



I'm sure you are, as long as you're not blind. I just run into many owners who are willfully so! Certainly does not sound like that's the case here.





There had been an existing bad repair of cracks in the cockpit that I ground out today. OMG grinding them out, the repairs were worse than I thought. Ground out glass that they had just filled with poorly-matched gel. No wonder it cracked again, it was so thick.



Yes, that sort of thing is certainly very common. You will see many recommendations on this very web site to make gel repairs in that way, as well as everywhere else.




I'm about to order some pigments for color matching and I stumbled across a post that you wrote a few years about about color matching. You talked through the mylar trick and said you did not know why it works but it does. I'll tell you why it works, in case it never hit you...

Polished gelcoat and wet uncured gelcoat have different specular reflectivity, with the polished gel being lower. Sandwiching them both under mylar, the polished gel with some spit on it, gives them both the same specular reflectivity.

The spectral reflectivity of an object has a direct effect on it's perceived hue and value. If it's lower, diffusing more like and reflecting less, it's going to scatter some wavelengths and reflect others, changing it's apparent hue. If it's more diffuse it's also going to appear darker because it's reflecting less light. Your solution fixes that.

I ordered some mylar, lol.


Sure, that sounds like the right science!It makes a huge difference. Packing tape is also clear mylar and works fine too in a pinch,
but it's not as nice as mylar sheet. In the old days we used a cigarette cellophane.






Chain plates are made. New traveller is done. New stainless handrails are almost done. They are works of art. Turns out Dan the fabricator worked for Palmer Johnson for a bunch of years. I'm feeling a bit super-yachty. So now I just have to get the deck done so I can start putting the poor girl back together.



Awesome! It's great when you can find a good steel guy,
they can crank out a lot of top shelf stuff real fast. Just had my new steel guy cut a hole in an 82' er that we just had him fab a new bow roller for.
Guy cut a perfect 3" circle for the center pin with a plasma cutter, looked like a hole saw cut, free hand, hanging off the bow. Mad skilz! Now I gotta paint it...





Reminds me I need to inventory fasteners and start ordering new ones. It's gonna be expensive. I'm pretty sure at this point that I could have parted the boat out and gotten more than it's market value. As I've stripped stuff off I've been pricing it, just to toy with replacing stuff. Dear god, the Perko hawsepipe inserts are $100 each, and I have eight of them. Ridiculous.

Yeah, but nobody wants a "used" hawsepipe insert! Keep at it man, sounds like you're making good progress!

[Suijin]

A little googling turned up that the thread on the mandrel is virtually proprietary...9mm x .7, and that a lot of people are peeved about it. The tool is super popular among auto body workers and it's being dismissed as a non-professional tool that it was designed this way. Will probably order back-up backing pads so I have them. The tool was not cheap.

Never underestimate what people will pay for used boat hardware on eBay. It's nuts. The girl working on the boat next to mine, an old Mariner 38, has finally thrown in the towel and is parting it out. She's confident she can get more than she paid for it selling off piece by piece. And then she's going to buy a wooden boat. Out of the frying pan and into the fire!

My current dilemma is my Yacht Specialties pedestal. It's in good shape, but now would be the time to install a new Edson. But none of the damn parts except for the wheel and compass are interchangeable. It would cost a bomb, I'd have to drill new mounting and guard feet holes, etc. So it's staying but will need some modification to fit the new 1-1/4" helm guard.

I should have the finish rough hgrinding on the non-skid done today, then on to a "quick" fairing of it and dealing with the gel cracks. A few of the gel cracks go under the jib tracks, which is the only hardware I did not pull. Some of the mounting bolts/nuts are glassed over and/or right above bulkheads on the underside, and it's not cored so I was not going to pull them. I think I'll leave them and if the cracks come back again from under them, I'll deal with it then. In a perfect world they would come off, but this project is already behind schedule. Making a few concessions to getting it done and this is one.

Minaret, how fine on sanding do I need to go on the ground off non-skid to not get swirl marks printing through the painted on non-skid? Assuming that the flat and particles will cover and don't want to make work for myself, but don't want to underestimate either.

[minaret]

Originally Posted by Suijin

A little googling turned up that the thread on the mandrel is virtually proprietary...9mm x .7, and that a lot of people are peeved about it. The tool is super popular among auto body workers and it's being dismissed as a non-professional tool that it was designed this way. Will probably order back-up backing pads so I have them. The tool was not cheap.

Never underestimate what people will pay for used boat hardware on eBay. It's nuts. The girl working on the boat next to mine, an old Mariner 38, has finally thrown in the towel and is parting it out. She's confident she can get more than she paid for it selling off piece by piece. And then she's going to buy a wooden boat. Out of the frying pan and into the fire!

My current dilemma is my Yacht Specialties pedestal. It's in good shape, but now would be the time to install a new Edson. But none of the damn parts except for the wheel and compass are interchangeable. It would cost a bomb, I'd have to drill new mounting and guard feet holes, etc. So it's staying but will need some modification to fit the new 1-1/4" helm guard.

I should have the finish rough hgrinding on the non-skid done today, then on to a "quick" fairing of it and dealing with the gel cracks. A few of the gel cracks go under the jib tracks, which is the only hardware I did not pull. Some of the mounting bolts/nuts are glassed over and/or right above bulkheads on the underside, and it's not cored so I was not going to pull them. I think I'll leave them and if the cracks come back again from under them, I'll deal with it then. In a perfect world they would come off, but this project is already behind schedule. Making a few concessions to getting it done and this is one.

Minaret, how fine on sanding do I need to go on the ground off non-skid to not get swirl marks printing through the painted on non-skid? Assuming that the flat and particles will cover and don't want to make work for myself, but don't want to underestimate either.

Don't take your initial sanding past 80, then apply at least three heavy coats of gelcoat as a primer (4 is better) and sand out to at least 220 (320 is better) before applying paint. After you apply primer gel guide coat and skip straight to 150 or even 180, depending on whether you roll applied or sprayed. Use either PVA or surface seal, not both, with no accelerators. I reduce with MEK and/or styrene monomer to promote flow. Keep at it!