Priming... Just a few questions.

[todd gustafson]

Hi all, I just want to start by saying thanks for all your help, this site is worth it's weight in GOLD..... Hat's off to Tim for the start up.

I have spent many hours scanning the posts. And hope my questions are not repetitive.

Recap: "Rosie" is a 1976 Tartan 27 that are giving a face lift. Topside paint (R&T). All hardware, portlights, teak, have been removed. Decks sanded, all thru deck holes filled (drill & epoxy fill before putting hardware back on after final paint), epoxy filler where needed, 4 new deck scuppers, non-skid sanded down smooth...... Many hours spent sanding...... & re-sanding.... Cleaning. I think we are now ready to start priming..... We are using Awlgrip high build primer 2 coats (deck only- hull is in very nice shape may not need a high-build) as well as 545 primer (2 coats).....We intend to prime the entire deck before moving to hull.
We will have badger brushes and mohair rollers in multi sizes sizes..... trays, drop cloths, clean rags, thinners, reducers, cleaners, gloves,masks......etc.
Taped off portlights, all chainplates, large thru decks, companion way teak trim.

Questions we have:

*Is it realistic to prime the whole deck in one pass or should we break it up....deck,...... doghouse,......cockpit?

*Where to start? Where to stop?

*How long do we have to re-roll over a wet edge? Is it seconds, minutes, ??? ( knowing the deck will have most non-skid where the edge could end in if needed)

*Do i have more "lee-way''(learning curve) with the high-build knowing it will be sanded for the 545 which will act more like the final covering?

*I have read that much of the corners, edges, etc. is better off using a brush rather than a roller.....true or not?

*How much time do i have till i need to remove the tape, can i do multi coats before removing or do i remove after each prime and re-tape?

These are the questions i have at this time.............

Thanks Much
Todd

[Rachel]

I am just going to butt in here - politely, I hope :) - and mention that "topsides" is the part of the hull between the gunwale and the waterline. I read before that you were preparing to paint your topsides (in another thread), so that's what I was visualizing, but now I'm pretty sure you are painting the deck only (or maybe you are doing both? If so... never mind!).

[todd gustafson]

Rachel
We are painting waterline up........:) sorry for any miss-quotes or verbiage..... Thanks

Todd

[todd gustafson]

We are painting both hull and deck........This post is mainly for the deck..... The priming of the hull is much more forward which we will do after the deck.

Todd

[Rachel]

Thanks for clarifying, Todd. I couldn't quite tell and it seems that oftentimes people say "topsides" when they actually mean the deck.

[Tim]

*Is it realistic to prime the whole deck in one pass or should we break it up....deck,...... doghouse,......cockpit?

Yes, it's realistic; not only that, you should consider your rounds of primer to be dry runs for the topcoat later on. You'll learn a lot about your deck and how it makes the most sense to proceed through those first few coats of primer, and this info will be invaluable when it comes time to topcoat.

Some decks are so complex (or large) that this is less feasible, but on a T-27 it's certainly possible--you just have to learn how, and this means you, individually, on your individual boat, based on your painting environment, access to the boat from staging, etc. Remember to avoid painting yourself into a corner, and to ensure that hard-to-reach places like cockpits get done first.

Remember also that you want to sand everything as soon as possible following application (i.e. next day, as soon as the paint's cured sufficiently). These epoxy primers become increasingly and annoyingly hard with only a slight passage of time. So if you have time constraints, don't prime more than you can sand the next day. But I'd not recommend breaking the priming up into several stages; the process is going to take you long enough as it is without spreading out what's a day's work into two or three when it's inherently unnecessary. But let your experience and comfort levels be your guide. Pushing things will only get you in trouble.

*Where to start? Where to stop?

You'll have to figure this out by trial and error (or at least by looking at and thinking about your own deck). Think of a place on your deck where an overlap dry seam will be least visible, and use this as a starting point. Usually this is at an inside or outside corner, or a section of sidedeck where the paint width will be minimal, or beneath a piece of hardware...you get the idea.

Lap marks and dry edges aren't much of a problem with the primer coats since you'll be sanding, but again, you want to learn how best to do things when it comes to the topcoat, where wet edges are crucial.

(Advance notice: if you use LPU topcoat (Awlgrip or Alexseal; I don't know about perfection, which is completely different anyway), note that it acts completely differently than any of the primers, so don't let success with the primer go to your head. If you apply topcoat the same as you do with the primer you'll end up in trouble. It's a whole new learning curve, though one that builds nicely upon the primer experience. Just don't expect it to work the same way.)

*How long do we have to re-roll over a wet edge? Is it seconds, minutes, ???

A minute or two, depending on atmospheric conditions, paint film thickness, and type/amount of reducer you have at that given time. Less if it's hot (or the primer has tons of reducer), more the cooler it is--but only to a point. Again, you'll pick up on the specifics as you go; there's no hard and fast rule here. Be prepared to learn as you go. Work quickly, but not hastily.

Learn the paint; throw your preconceptions out the window and let the paint teach you how it needs to be applied. Practice with the paint before you jump on the deck. One good thing about these paints is their pot life is very long, so you're in no danger of the pot kicking off no matter how long you take once mixed. You'll need to add splashes of reducer as you go to replace evaporation; this applies to all coats of all primers and paints.

*Do i have more "lee-way''(learning curve) with the high-build knowing it will be sanded for the 545 which will act more like the final covering?

Yes, but don't expect the high-build to level out smooth and flat. It won't. It's thick and dense, and no matter how much reducer you put in you're going to end up with a texture, no matter the means of application. This even occurs with spray application.

Remember that the ultimate goal of your primer is to have consistent coverage over the entire surface when all is said and done. You'll sand away most of the high build to smooth it (4 coats recommended by roller application to minimize this), and the finish primer may end up translucent, but you want to avoid burning through (some is probably inevitable). You don't need thick coverage--just consistent coverage.

*I have read that much of the corners, edges, etc. is better off using a brush rather than a roller.....true or not?

Maybe, maybe not. Beware of these generalities. Find out what works for you. But you'll need some brush work, almost certainly. I recall that I ended up simply brushing most of my deck when I rolled/tipped it in September 2000 (a long, long time ago) as the surfaces were too small for effective use of the roller vs. the annoyance of extra tools and so forth to juggle. I'm sure I used the roller, but did more brush work towards the end than I did at the beginning.

*How much time do i have till i need to remove the tape, can i do multi coats before removing or do i remove after each prime and re-tape?

I am pretty sure you said you're indoors, so you can leave the tape on indefinitely. I have never had a problem removing tape covered with multiple primer and topcoat layers, but again, when you go to remove it, be prepared to learn the proper technique.

If the surface is properly prepared, the tape won't stick unnecessarily where it shouldn't, and won't pull up the new paint either. If you get "puddles" over the tape in some areas, you may need to score the edge with a sharp knife, but you'll figure that out when the time comes.

This also assumes you're using good tape. I like 3M #233 at this particular time.

[todd gustafson]

Thanks Tim, as i said before....... great site, great information. And to answer your question the boat is in a heated garage.

Now that i know we have to sand right away(next day) i'll have to push cleaning-prep to Saturday morning and priming in the afternoon....

New Question

*What grit(s) of sand paper for the highbuild between coats?

I have photo's i intend to post, just have to find the cord for my camera.:)

Todd

[Hirilondë]

I rolled and tipped the primer/high build coats on my boat, a Renegade that I painted completely. I did 4 coats of primer in one non-stop marathon day (app 16-18 hours) with no sanding between coats. Then sanded the entire boat in a marathon day the next day. It was the most brutal weekend of boat work in my life. But I figure I saved 3 weeks elapsed time and a lot of sanding hours. This is not for everyone, but is an option.

[Tim]

*What grit(s) of sand paper for the highbuild between coats?

I'd suggest 220 (definitely no finer).

Since I have sprayed exclusively for the past 10 years, I don't have to sand between coats (sorry), so I'm no longer sure what's recommended, but I prep the substrate to 120 grit before high build, and sand the high build with 220 grit before applying finish primer. I sand finish primer with 320 grit before spray application of topcoats, all per manufacturer's instructions and reinforced with experience.

[Tim]

I rolled and tipped the primer/high build coats on my boat, a Renegade that I painted completely. I did 4 coats of primer in one non-stop marathon day (app 16-18 hours) with no sanding between coats. Then sanded the entire boat in a marathon day the next day. It was the most brutal weekend of boat work in my life. But I figure I saved 3 weeks elapsed time and a lot of sanding hours. This is not for everyone, but is an option.

Definitely a good time-saving way to go about it for those who have the consolidated time, skill, and inclination for such a marathon.

[todd gustafson]

Well, it was a long day.....14 hours.

Cleaned the deck with TSP as well as M.E.K. to make sure it was clean, taped off all openings.......and went to town with the High-Build Primer, we started in the cockpit......still not knowing what to expect with rolling, as you all said it takes awhile to get the feel of the paint..... and when it's time to thin a bit.

We started in the cockpit and worked our way counter-clockwise till we make it back to the cockpit. The first coat was going slow and started to speed up when we could use ladders and work off the boat.

We ended up putting on two coats..... the second coat went on in a quarter of the time....and much less paint.

In the morning we plan to sand.........

Question: Is there an easy way to know when you can sand? I realize it depends on the temp and all........is there a feel, a look as to what to look at ?

Thanks Todd

[Tim]

You'll know. If it's not ready, the paper will gum up.

[Zach]

Also buy a few different brands of cheap black spray paint for your guide coat.

Sometimes they gum up, some times they don't. The last few months I've been using rustoleums cheapest enamel...

You can also un-gum a piece of sandpaper with a rubber abrasive cleaning stick. Jet is the brand I've always seen, most places that have belt sanding belts have them. Works to stretch the life of good sandpaper.

Zach

[todd gustafson]

Well, back to sanding the high-build..... it was a nice break to get away from it ......We are getting hit with as much as 12 inches of snow today so i might as well work on the boat even if it's sanding ...

I have heard about the guide coat........ I take it that you would sand till all paint is just sanded off as to not burn thru, correct?

Would you spray the entire deck.....or spot spray?

We took lot's of pic's..... will load later today:)

Todd

[Zach]

The guide coat gives you a visual indication of when you have worked through a grit, and shows the low spots and pin holes in the surface.

You hold the spray can 12 inches or so from the hull, and lightly mist a coat over the whole hull. The mist should be dry when it hits the hull. (check to see if your cheapo black spray paint gums up the paper first... before doing the whole hull.)
Lately I have been using the large cans of Rustoleum enamel, as it hasn't been gumming the paper. Stuff changes, so always check a small area before shooting the whole boat.

When you go over the surface and the guide coat is off, you are done with that grit. If you burn through anywhere... add another 2-3 coats of primer,or better yet roll the hull in awlquick two or three times as you have high spots in the hull and have to add enough material around them to sand smooth. You'll run your da or random orbit sander up and down in overlapping passes, and then right to left overlapping over an area as wide as you can comfortably reach before moving on to the next area... overlapping into the old all the while.

Where the roller stipple, and black mist is still around, are your low spots. A durablock long board http://dura-block.com/ and a roll of 3m gold in 100 to 120 grit inline paper will show the lows quickly... But it does depend how fair the hull is to begin with. These get used on the diagonal pushing along the length of the boat 45 degrees from toe rail to boot stripe, each pass an inch or so further along than the next. The other way if you have full staging is to skew the board about 60 degrees from horizontal and walk down the hull its whole length moving up from the boot stripe an inch each pass until your guide coat is gone.... Which is the ideal, but more work. This gets everything straight... which is different from smooth. Smooth means your finish is shiny, straight means it doesn't have waves in it.

If there are a lot of lows you can drop to 80 grit and burn off most of your coat of high build, and put on another coat afterward. If the hull was slick and smooth without ripples and waves, you probably don't need this step, but if it has been painted and patched before it would be worth your time. A flexible long board spans the minor lows that reflect light at a different angle, and will show flat spots around repaired areas that were not blended in... Durablocks are available at your local auto body supply shop, along with the 3m sandpaper. 10-15 bucks for the block, 40-44 bucks for the roll of sandpaper. The 24 to 30 inch blocks are the ones you are looking for... along with one of the 1/3rd sheet blocks for tight corners. I prefer these blocks above any of the others I have found... and I've tried pretty much all of them including shop made goodies.

You can also rip a piece of 1/2 x 3/4 clear straight grained pine and rub blue chalk all over the face of the batten. Then rub this batten against the hull. Your lows will show that are bigger than your long board will show you. You can also use a piece of thin metal like strapping used to hold things to wooden shipping pallets, and metal straight edges held flat to the hull. Anything that bends fairly will show air gaps, or make noise when you tap along the length while someone else holds one end. Take a pencil and mark where the gap starts and add a little putty between the lines.

When you are filling the lows, use as stiff a spreader as you can, and as wide as it takes to span the low. Some lows require pulling on diagonals, one way and sanding... then pulling the opposite direction if they are on a tightly curved surface. I tend to pull up and down once, sand, and then pull left to right. On flatter stuff I pull it once with a west systems plastic spreader, and then come back and pull most of the putty off with a 12-24 inch sheet rock taping knife. A batten can sometimes be helpful to pull putty around a tigher curve... but generally it takes 3 rounds of puttying to get something perfect as even the epoxy putty shrinks.

When you find pin holes blow off the surface, or use a paint brush and get the dust out of them and fill them. If you are between layers of primer, my favorite after a lot of testing different products for shrinkage is evercoat ultrasmooth. Applied with a razor blade... Awlgrips awlfair works well, but applied with a plastic west system glue mixing stick and left just proud of the surface as it will pull out of the pin hole if pulled with a razor blade. By this point a plastic squeedgee isn't of much use, as it leaves to much material on the surface to sand off. A quart of evercoat should do a few boats... Mix up some around an inch blob, 1/4 inch tall. A 1/4 inch line of blue hardener is all it takes.

If you read awlgrips bible of application, they account for polyester glazing putties to fill minor imperfections between layers of primer. Not, directly on or under awlfair... Polyester putties shrink to much to use for anything deep, they dry to sanding 15 to 20 minutes after application. Polyester putties are for stuff that is the size of a dull pencil point, and lows you can just feel with your finger tips. My rule of thumb is that anything that catches your fingernail should be done with an epoxy putty, like awlfair. Awlfair takes a half day affair to sand in winter, 3 hours in summer. If there are 80 spots that need attention... use awlfair, if there are 8, use ultrasmooth. It is the only one that gets my endorsement. 3m's piranha putty runs, 3m's acry white shrinks for days... All the bondo lineups grain size is to big, and don't pull smoothly or end up red and hard to cover.

While the quick sanding is the primary reason I use ultrasmooth, the other is that it takes 3 coats of 545 to cover awlfair... It takes 5 to cover and have material to sand without it showing back up. Ultrasmooths light blue stays covered after the next sanding. There are also white hardeners, but I have my crew use blue so they know it is mixed...

Do not use a sharpie marker to mark anything requiring filling, a pencil is all that is allowed. Markers will bleed through the primer.

[todd gustafson]

Zach
We tried the Guide Coat application on the hatch cover and didn't like the effect on the surface, very hard to sand out and gummed up the disk often.....

I noticed that i was looking to much at the Guide Coat, where i sanded and didn't, where to sand next..... I like to "feel" the area that im sanding, often running my hand over a 12''-18'' spot.....feeling for low spots, rough areas, etc.. and can i go

I could see where it would be good for applications of fairing the decks that have been recored and major repair work as been done.
Todd

[todd gustafson]

Hi all, we are ready to apply the 545 primer. Can we apply multiple coats (in the same day) without sanding between coats? How long do we have to wait before sanding?

Thanks
Todd

[bobp]

[I just noticed that Todd posted the same questions as I asked below, but I think I'll post this anyways. Sorry for the redundancy]

This post will serve two purposes. The first is to introduce myself as this is my first post on this forum. I'm a co-owner of Rosie, the same Tartan 27 as Todd's (the OP). I'll reiterate what others have said before - this is an extremely valuable resource. I don't know how people coped with challenging DIY projects before the internet.

The second purpose is to ask a question about priming. We've completed the high build priming and sanding, and plan to start the 545 priming tomorrow. We were hoping to get two coats in, but the data sheet says this: "allow 12-14 hours between coats. Light sanding between coats will improve appearance" *. So the question is, what would be the down side of not sanding? (Someone here said sanding builds character, and if that's true we're approaching Mother Theresa territory!). If sanding is definitely recommended, how long should we wait after primer application before building more character?

* As I understand it, with at least some two part systems such as epoxy, the bond is stronger if you apply additional coats before the previous one fully cures because it's a chemical bond. After a coat cures, it needs to be sanded before being recoated because the next bond is mechanical - kind of like miniature velcro. I take it that the 545 is different since the data sheet doesn't seem to leave this option open. Does anyone have more information on this?

[Rachel]

Welcome, bobp!

Any chance of a stray Rosie photo? ;)

Rachel

[todd gustafson]

Hi Rachel, I have many pictures to "show and tell" but am still trying to figure how to attach from Photobucket....:):)


Todd

[Tim]

You can apply as many multiple coats as possible in a day as long your application tools don't lift or otherwise adversely affect the previous coat. How soon this actually is depends greatly on atmospheric conditions, amount of reducer in the paint, and other factors.

The solvents in the paint are strong, so the new paint will (and is intended to, in wet-on-wet application) liquify the layer beneath (when applying before each layer has cured). So you'll have to see how it goes and do some testing to find the appropriate time lapse between coats.

Of course, if your applications are uneven, or poorly leveling, or contain runs, sags, and drips, it's fruitless to apply additional coats before sanding out the flaws. But with a nice, smooth, even layer, properly applied, you can go wet-on-wet as long as you can do so without creating a mess of the coat beneath. Use the data sheets as a guideline, and work off some test samples so you can find the right time to apply an additional coat.

[bobp]

Thanks Rachel for the welcome! As Todd mentioned he's got the project pictures. I'm going to try to attach a picture taken a few years ago at a regatta at our yacht club. Wish me luck.

rosie_1.tif (248.16 KiB) Viewed 9921 times

Hoo hoo - it worked!

Thanks Tim for the feedback. So if we find that putting a second coat on would make a mess and decide to wait, would it be a mistake to not sand everywhere? For example, could we just sand out the drips and sags and prime over the rest unsanded, or would there be problems (e.g. a weak bond)?

[bobp]

Of course, if your applications are uneven, or poorly leveling, or contain runs, sags, and drips, it's fruitless to apply additional coats before sanding out the flaws.

Is the problem that putting a coat over a drip, for example, would make it more difficult to sand it out later, or that the drip doesn't cure completely, or something else? The reason for asking is that our experience with the high build was that a single coat was very easy to burn through, but area's that had two coats back to back was better in that regard. In we could go back in time, we would definitely have done the marathon approach and get all coats down in one day. Not just to save time but that it would have resulted in better coverage. Is the 545 different enough that this thinking doesn't apply?

[Tim]

No, I meant that sanding out a drip or what have you through additional coats seems silly. If the drip is in the 1st coat, say, then to sand it out you'll need to sand through all the coats above it, if you continue to apply, and then all you've really done is wasted time and product. Major flaws need to be sanded out before recoating.

You really shouldn't have this problem if you're careful with the paint and have given yourself the appropriate learning curve, but I was just offering an example.

Once the primer goes past the time limit for overcoating without sanding, you have to sand it. Don't shortcut this important process. Learn to sand effectively. My feeling is that if it's cured enough to sand at all (i.e to sand drips only as you suggest), then it's past the safe hot-recoat period and you must sand it all to ensure proper adhesion of the next coat. Just my opinion based on general paint experience, not necessarily backed by the science of the paint. You don't want your paint peeling of in sheets. The efforts of sanding are well worth it, and are soon forgotten when the job is done.

These primers are very easy to burn through. Multiple coats before sanding (within the appropriate time period) is a good way to help avoid this problem, as well as get the job done far more quickly and efficiently.

And yes, I once said here that sanding builds character. What kind of character I don't know...but character nonetheless.

[Hirilondë]

My feeling is that if it's cured enough to sand at all (i.e to sand drips only as you suggest), then it's past the safe hot-recoat period and you must sand it all to ensure proper adhesion of the next coat.

I think that is the safest rule of thumb one can go by for determining the hot recoating window for any curing material, epoxy, paint or whatever. Some products may have a longer window, but unless the manufacturer tells you other wise this will keep you out of trouble.

And yes, I once said here that sanding builds character. What kind of character I don't know...but character nonetheless.

Hmmm, I always thought pain was what built character. At least that is what my father always told me when I hurt myself as a kid. Of course I never believed him.

[bobp]

Well let's see, how to put it ... Holy Smokes!

The first coat of 545 is on, and it is most definitely different from the high build. We didn't make it all the up the learning curve. The best we say that we can kind of see where the top of the curve is now.

We had two major issues. The first was that lint from the mohair roller got into the paint, and of course it's all over the deck now. We very quickly decided to go bush only, but even then the paint was contaminated. The lint was coming off the side of the roller. Have others had this problem? There was other miscellaneous debris too. We did make the mistake of not using a tack cloth. We cleaned with solvent immediately before painting so figured that should be good enough. It wasn't.

The second major issue was brush marks. There was only one drip, and it was from a hole on a vertical surface so I'm sure the paint got into the hole and came back out as a drip. There were no sags, but we've got lots of brush marks. Part of the problem was that the brush left lines that looked like marks, even after the surface leveled. You look from the side and it looks glossy, but from above you see the lines. So it wasn't easy to tell when the paint got too thick just by looking. My conclusion is that we needed more reducer to start with (25%?) and then add some more often. The data sheet said to use between 5-10%, but that was much too little. The temperature was probably in the 60's.

Initially, we tried to use one bush for application and one for tipping, but ended up just using one brush for both purposes. Was that a mistake and part of the bush mark problem?

Needless to say we didn't even consider applying a second coat. Tomorrow will be sanding day. As I understand it, we want to use 320. Is it better to go with wet or dry? Also, is there any chance of not burning through the primer while sanding the brush marks?

The good news is that we appear to have plenty of primer for a 3rd and possibly even a 4th coat.

[Tim]

Brush marks in the super-fine finishing primer are indicative of too little reducer, and/or application technique/materials. This primer should level extremely well when applied evenly and properly reduced.

You can use far more reducer than the data sheets suggest. Use what you need to make the paint flow and level properly and forget the data sheet, but don't reduce more than 50%. Remember to add splashes more throughout the painting process to replace what evaporates from the pot or tray.

You're likely to frequently burn through a single brush-marked coat in order to smooth it, so chalk this up to lessons learned, sand it smooth without undue worry about burning through (though avoid it to the extent possible), regroup, and try again, using your new knowledge that you learned the only way you truly could have: by actually doing the work. It's too bad the first coat didn't come out well, but you know more now and can use that hard-won knowledge to proceed.