Questions about Primer

[DBG8492]

So I think my boat was previously painted with AwlGrip.

The previous owner passed before we bought her so I can't ask him, and I didn't find any receipts in any of the boxes of records that were on board. Therefore, I don't have any guarantee of this, but when cleaning out the lockers in the flybridge, I found several containers of "AwlGrip Boat Wash" or some such.

Yes, someone could have bought that without having AwlGrip on the surface, but I also noticed that when sanding any of the white paint on the hull above the waterline, it doesn't sand right until you're below the topcoat. When I say "it doesn't sand right," I mean it's difficult to sand at all and once you get a bite, it doesn't sand smooth - it sort of flakes off. The layers underneath will feather easily, but getting the topcoat to feather is an extreme challenge.

I've heard that AwlGrip is famous for being difficult to sand and repair, with exactly these symptoms. Given all the clues, I think that this is what I'm dealing with.

So the question is: If I want to cover this - whatever it is - without sanding everything off, what's the best option? Will one-part primer work? Or do I have to go with a two-part epoxy?

Yesterday, I painted a thin test coat of TotalBoat single-part topside primer on an area at the aft end - probably 5 square feet. I thinned it 25% with the TotalBoat thinner - which is probably a bit steep, but I just wanted to test it. It seems to have cured nicely - no indication of any issues. It sands, and I can scratch it with my fingernail and it doesn't come off. What would I be looking for as indication there was a problem? Or is it one of those things that won't show up until later when everything comes off in chunks?

 

[sean9c]

I've sanded a lot of Awlgrip and most of the other LP's and never thought that they didn't "sand right". It shouldn't be difficult to sand, or sand smooth or flake off when you sand it. If it is flaking off when you sand it means that there is bad adhesion between the topcoat and whatever is underneath. The only fix for that is sanding all the topcoat off.
If you're priming with single-part primer I guess that means that you're just going to topcoat with single-part enamel. That should stick to whatever is on there now provided that you sand the old finish first. It also won't be nearly as durable as an LP.

 

[DBG8492]

I've sanded a lot of Awlgrip and most of the other LP's and never thought that they didn't "sand right". It shouldn't be difficult to sand, or sand smooth or flake off when you sand it. If it is flaking off when you sand it means that there is bad adhesion between the topcoat and whatever is underneath. The only fix for that is sanding all the topcoat off.
If you're priming with single-part primer I guess that means that you're just going to topcoat with single-part enamel. That should stick to whatever is on there now provided that you sand the old finish first. It also won't be nearly as durable as an LP.

I've heard probably twenty or thirty different times - in different places from different people - that AwlGrip is next to impossible to repair because it "won't sand right" - along with a list of issues when sanding it that sound like what I'm experiencing.

Not sure - maybe it was all people who applied it incorrectly. Or maybe this boat sat too long in the South Florida sun without being maintained and the paint has just gone bad in some places - IDK.

And yes, I was going to single-part both - but I am rethinking that plan.

We used Interlux on our sailboat and it was pretty tough paint. I used a "farm store" hardener in what I applied to hatches and other places where I thought there might be a need for it - but even in the areas where I didn't use it, it was pretty tough. Not sure about the longevity though as we sold it six months after painting it.

 

[RT Firefly]

Greetings,
Mr. DGB. We used all Alexseal products when we re-painted our 46' Cheoy Lee LRC. VERY user friendly. Longevity? Only kept the boat for 4 years afterwards and still shiny.

 

[Larry M]

If you’re doing all the preparation to paint, I wouldn’t use a one part paint. They are not as durable as a 2 part paint. We’ve had boats painted with Awlgrip polyurethane and AwlCraft acrylic urethane. Both faired well at 10 years. We painted exterior sections using a 1 part paint and were lucky to get 4-5 years.

 

[Southern Boater]

I've heard probably twenty or thirty different times - in different places from different people - that AwlGrip is next to impossible to repair because it "won't sand right" - along with a list of issues when sanding it that sound like what I'm experiencing.

Not sure - maybe it was all people who applied it incorrectly. Or maybe this boat sat too long in the South Florida sun without being maintained and the paint has just gone bad in some places - IDK.

And yes, I was going to single-part both - but I am rethinking that plan.

We used Interlux on our sailboat and it was pretty tough paint. I used a "farm store" hardener in what I applied to hatches and other places where I thought there might be a need for it - but even in the areas where I didn't use it, it was pretty tough. Not sure about the longevity though as we sold it six months after painting it.

Which ever way you choose to go, the job ahead is going to involve a lot of work, as you already know having painted previously. If the intention is long term durability and high gloss retention, the two component system is the way forward, as already mentioned by Sean.

I would definitely only use primer/undercoat, topcoat and thinners from the same system or company, there is too much grief and hard work taking it off again if there is incompatibility, and no recourse from manufacturer.

If you’ve bought International paint previously, like all the quality brands, it’s expensive.
Some get great results with the better brands of industrial paint, which don’t invest in big internet marketing campaigns, but are equally as good with durability, gloss retention and chemical resistance, which are the key factors.

I’ve just finished a 2K system and chose an industrial paint based on the advice of local boat painters. Factors being equal long life, durability, gloss etc but easy availability in this area for any touch up requirements from impacts, for example.

 

[sean9c]

I think that you're confusing the repairability of Awlgrip with just sanding Awlgrip. Awlgrip sands just fine. The problem with trying to repair Awlgrip is that normally after you spray your new coat you have to sand and buff it in order to blend it in with the existing finishes. Sanding Awlgrip removes the thin hard shell like layer that gives it it's durability. So while your repair might look fine at first after a few years you'll likely start to see it.

I've heard probably twenty or thirty different times - in different places from different people - that AwlGrip is next to impossible to repair because it "won't sand right" - along with a list of issues when sanding it that sound like what I'm experiencing.

Not sure - maybe it was all people who applied it incorrectly. Or maybe this boat sat too long in the South Florida sun without being maintained and the paint has just gone bad in some places - IDK.

And yes, I was going to single-part both - but I am rethinking that plan.

We used Interlux on our sailboat and it was pretty tough paint. I used a "farm store" hardener in what I applied to hatches and other places where I thought there might be a need for it - but even in the areas where I didn't use it, it was pretty tough. Not sure about the longevity though as we sold it six months after painting it.

 

[NWboater2]

This isn’t exactly what you asked but might be useful. My prior holby pilot was Awlgripped at the factory. When I had it repainted professionally they had no problem sanding but did have a problem getting the awlcraft 2000 to stick even when the original paint was gone. Second try they used awl something primer under the awlcraft 2000 and it was perfect when I sold seven years later.
Do not wax! Use the recommended polish, in the recommended manner.

I agree with others that the prep is so much of the painting project that you may as well use the best topcoat, over a proper primer, after you’ve done the hard part. They claim newer coatings are easy or at least easier to roll and tip. All the major two parters are excellent coatings. Good luck!

 

[Delfin]

So I think my boat was previously painted with AwlGrip.

The previous owner passed before we bought her so I can't ask him, and I didn't find any receipts in any of the boxes of records that were on board. Therefore, I don't have any guarantee of this, but when cleaning out the lockers in the flybridge, I found several containers of "AwlGrip Boat Wash" or some such.

Yes, someone could have bought that without having AwlGrip on the surface, but I also noticed that when sanding any of the white paint on the hull above the waterline, it doesn't sand right until you're below the topcoat. When I say "it doesn't sand right," I mean it's difficult to sand at all and once you get a bite, it doesn't sand smooth - it sort of flakes off. The layers underneath will feather easily, but getting the topcoat to feather is an extreme challenge.

I've heard that AwlGrip is famous for being difficult to sand and repair, with exactly these symptoms. Given all the clues, I think that this is what I'm dealing with.

So the question is: If I want to cover this - whatever it is - without sanding everything off, what's the best option? Will one-part primer work? Or do I have to go with a two-part epoxy?

Yesterday, I painted a thin test coat of TotalBoat single-part topside primer on an area at the aft end - probably 5 square feet. I thinned it 25% with the TotalBoat thinner - which is probably a bit steep, but I just wanted to test it. It seems to have cured nicely - no indication of any issues. It sands, and I can scratch it with my fingernail and it doesn't come off. What would I be looking for as indication there was a problem? Or is it one of those things that won't show up until later when everything comes off in chunks?

Awlgrip sands like any other paint. My boat was painted with Awlgrip 24 years ago and it still looks new. Repairs are easy - sand, airbrush primer and topcoat, wet sand over spray with 600/1000/1500/2000, then polish.

If the top coat flakes, either it isn't Awlgrip, or the primer was incorrect or aged so the chemical adhesion between the primer and top coat never happened. Since Awlgrip is usually applied by a pro, I suspect it's not Awlgrip, because a pro wouldn't have a problem with adhesion.

You'll only get a few years from a single part paint.

 

[DBG8492]

After reading the responses here and talking to some others here in the yard, I'm going to agree that in my case, whatever topcoat was applied has was either done incorrectly or has simply aged without being maintained. As such, we will go back and ensure that wherever adhesion is failing, it's sanded to the areas that will feather rather than crack and flake - which is going to be a lot.

I'm still undecided as to which primer/topcoat I'm going to use, but time and budget - as always - will play their parts in the decision. Yes, we have spent significant time working to get the hull prepped and ready for painting - far more than I would have liked. However, I'm not so sure at this point our budget is ready to spend 5x the difference in price for paint/primer. Especially given how much we're going to spend on the bottom - which is a whole OTHER story.

So a decision will be made eventually and we will live with the consequences regardless

Thanks for all the helpful advice!

 

[Sleeping Bear]

Just finished a job with awlgrip, it is far and away the best paint I have ever used. The hull was painted 10 years ago and still looks new. The transom didn't get the awl care applied every year, and that is what I just repainted.

Compared to other products I have seen awlgrip gives a far superior finish.

 

[REO]

Since we are talking about paint--I recently re-pained one side of my boat with Alexseal. The stuff is amazing. I used a small roller, and followed the directions on the boatworks today utube channel. Were it not for a small amount of dust I can see no difference from the other side that was professionally sprayed several years ago. You have to get really close with a strong light to see that it was rolled. The only problem, and I suspect that this is an issue with some other paints, is that Alexseal does not play nice with others. If you are painting over another product trouble could show up several months later. I wish I knew a solution to this for future projects, as I am in love with this stuff.

 

[sean9c]

I'm not sure why Alexseal over an other LP or appropriate primer would be a problem. Also would think if there is going to be a problem you'd know right away.

Since we are talking about paint--I recently re-pained one side of my boat with Alexseal. The stuff is amazing. I used a small roller, and followed the directions on the boatworks today utube channel. Were it not for a small amount of dust I can see no difference from the other side that was professionally sprayed several years ago. You have to get really close with a strong light to see that it was rolled. The only problem, and I suspect that this is an issue with some other paints, is that Alexseal does not play nice with others. If you are painting over another product trouble could show up several months later. I wish I knew a solution to this for future projects, as I am in love with this stuff.

 

[Bmarler]

Alexseal will work with any properly applied 2k primer/sealer, or any 2k urethane paint in good condition and properly sanded. My experience with alexseal is that it has a really long flow time. That’s why it works so good as a rolled or brushed finish. First time I sprayed it I was really surprised by the suggested time to recoat. Don’t rush it or you’ll be sorry.
If there’s any question as to the integrity of the substrate, an adhesion test should be done so you know the existing coating is holding well.