Awlgrip Question

[DennisDW]

Is there any reason why I cannot spray awlgrip directly on old, degreased and well sanded gelcoat? Areas where repairs have been made will get 545 brushed on and sanded smooth but their application guide suggest the topcoat should always be over 545 in all areas. Has anyone skipped the 545 on good gelcoat? This is a deck and cabin sides repaint.
Thanks Friends,
Dennis

[osirissail]

If you are going to spend all the money AwlGrip charges for their paints, you should carefully follow the procedures for applying it. Otherwise, you might just have used "Sears Best." There are a lot more economical paints like Petit EasyPoxy which gives a very good result with minimal effort.
- - Specifically, AwlGrip 545 covers the whole area to be painted to give you a good opaque base so color changes in the underlying hull/gelcoat do not alter the purity/conformity of the final topcoat color.
- - Normally, if you really examine your gelcoat closely, even in areas not damaged or repaired you will find huge numbers of pits and pinholes and other blemishes that will directly show up in the final topcoat without a 545 base coat.

[minaret]

Yup, gelcoat is often fairly porous. You will be very unhappy if you try to spray awlgrip over it without priming. Usually when you are shooting the 545 you will see the pinholes clearly not filling on the first coat. By the second or third pass they fill up nicely. I've done boats which had such severe porosity in the gel that they wouldnt fill at all when sprayed and we had to brush on a coat of 545 to work it into the pinholes.

[boatsmith]

A very skilled guy taught me that white gelcoat over new glass work makes excellent primer under Awlgrip. You do need an even base color to end up with a uniform color, particularly if using a light color. And if you want a smooth high gloss finish you must paint over a smooth surface. The Awlgrip will stick to new well sanded gelcoat. Gelcoat is much harder to sand than 545 but is also much cheaper.

[Opie91]

You will be much happier with the final result if you use the 545. Like mentioned above it hides a lot of imperfections. Also it sands out quite nicely.

Good luck.

[minaret]

A little trick with 545=If you are using 545 white-as opposed to the grey-you can throw a little of the topcoat color base into the mix. This will tint your white 545 towards the color of your topcoat, allowing you to get coverage on the topcoat quicker and with less product. This makes a huge difference with warm colors (yellow, red, etc.), which don't cover well at all. I've seen red awlgrip take twice as many coats to acheive coverage, it has much less pigment in it and therefore much less opacity. So if you were coating red you would throw a little color base into the primer, and your white 545 would be pink. It really helps with all colors though. This technique is approved by Awlgrip, they even mention it in their application guide. On the other hand, I really like 545 grey for dark colors, because it changes color when you sand it. That makes any holidays in the sanding really obvious, it's like a built in guide coat. Makes a big difference when your prep crew has some newbies, or a hangover.

[DennisDW]

Thanks everyone for the great advice. Now this question; given a fair surface, can I spray the 545 and then topcoat a few hours later without sanding for a chemical bond? Does the 545 go on nice and flow out well? Once I spend hours masking the intricate deck layout I'd like to paint coat on coat to cut back on re-masking after walking on it. Then there's the florida sun and evening thundershowers to deal with. Ah, life in paradise.
Dennis

[minaret]

You can chemical bond topcoat to 545 but it's not a good idea if you want to acheive a quality finish. We do this sometimes on request in the yard, but generally only on stripes. The problem is that 545 is not designed to flow on the surface. And there are no reducers for 545 to help you acheive flow. This means that 545 will always come out with a certain amount of peel. When you spray topcoat over it, it will accentuate the peel due to the high gloss and very thin nature of awlgrip. If you have a lot of experience using spray equipment, and you use high pressure equipment (Binks 2001 is my choice) instead of the more modern and environmentally friendly HVLP equipment, you can get a decent enough finish that some people wouldn't notice. It's not easy though. And in most states it's not even legal. Sanding 545 actually goes really quickly too. It's not a step thats worth skipping, really. Oh, and dont sand your 545 with anything less than 400 grit, it'll show if you do. Many people sand 320 for prep on 545, which is OK on a DA, but 320 hand sanding scratches will show up in your finish. And I hope you are taping with fineline, anything else is unnacceptable for LPU. Good luck and have fun!

Ps-Another problem with chemical bonding is the tape edge afterward. If you are shooting white LPU over white 545 it's not a problem, but if there is a color difference between your topcoat and primer you'll be able to see it when you pull tape, especially if you've had any bleedthrough. Usually we shoot 545, sand it out, then pull tape and retape just a hair outside the primer line. This gives you a chance to fix any bleedthrough of the primer, and allows the topcoat to cover the primer edge so you dont have that micro thin line of a different color showing. It also helps you to really rub out your fineline so you dont have bleedthrough on the topcoat, which is much more likely than bleedthrough on the primer. Remember fineline changes color when you have rubbed it out enough. I like to use a spoon for tape rubbing. Old timer's trick that helps you get the corners...

[Jim Cate]

Hey Minaret,

This isn't my thread, and I'm not currently doing any painting, but I'd still like to thank you for your informative, knowledgeable and useful posts here.

Well done!

Cheers,

Jim

[minaret]

Thanks for the appreciation Jim. I spent the last 18 yrs. in the yard helping other people to prep for their cruising dream. Now that it's almost my turn I find I have a little more time on my hands to try to help others with their questions regarding boat work, and try to learn a little more myself about the fields outside of my specialization (structural and cosmetic, not systems). Always happy if I can help out, particularly if I can help people NOT replicate some of the many mistakes I've seen in the yard. It's sad when people spend a lot of their hard earned money for poor results. Have fun and thanks again!

[minaret]

Oh and try taping your deck radius' with 1/4" fineline. If you have a larger radius layout that is. Unless you are a master of the razorblade method, most people use a bunch of little pieces of tape to make a radius. This makes a less than perfect curve. If you use 1/4" fineline you will find you can bend it into a pretty tight curve with no wrinkles, in other words it will edge-set. This is why they make it. Then you can tape all your radius' in 1/4" with a perfect curve and then rough tape regular blue masking onto the 1/4". Takes a little while but makes a perfect radius. I myself prefer to lay down a piece of 2" over the whole corner, lay out the radius with a compass and light pencil, and cut it with a razor. This is tricky because you have to cut the tape without scoring the substrate, it takes a surgeons hand, but makes perfect radius' very quickly. Takes practice. Also the compass will make perfect radius' at any angle acute or obtuse. I find it harder to do this using a circular object, the usual layout method. An outside radius is easy to layout, an inside radius takes a little trickery with the compass, but you'll get it if you stare at it for a little...

[DennisDW]

Thank you Minaret and all for the great information. I completely agree about spending a little more time and effort for a proper job. Especially considering the cost of materials. On that note, I'm a doctor (yes, I'm doing my own work) and I'm constantly shocked by the price of the pharmaceuticals I inflict upon my patients. This stuff shocks me more. Yikes!

So I will prime and sand everything before top coating. Any advice regarding activator and reducer in 90+ degree weather? I will be using an old fashioned detail gun since there are no large panel sections.

Thanks again. It's great to get some real world experience that the application guide is short on.
Cheers,
Dennis

[minaret]

Use the spray converter with T0005. If you try to use brushing converter for hot weather, as some do, it will probably work out but you might be surprised at how long dry time is. You may have problems with dust or bugs as a result(bugs love the sweet smell of wet awlgrip). Most people don't use straight T0005 either, for the same reason. You can mix all of the reducers into your own special blend to acheive perfect flow, and proper mixing for your conditions is probably about 80% of acheiving a perfect finish. The magic of mixing reducer is a huge part of the game. You should consider using Awlcraft instead of Awlgrip if you are not an experienced applicator, it's a little more forgiving. It is also much easier to do repairs on later, it goes on a little thicker and wetsands and polishes nicely. However for deck waterways, the extra hardness and durability of old-school awlgrip is a bonus. Depending on how hot it really is you might heat up your T0005 with a little T0003. Or you might want to cool it off by mixing in some T0031 brushing reducer. Brushing reducer is extremely cool and will give your very long open times. If it is truly hot, you can use straight brushing reducer with the spray converter. Never spray in direct sunlight or any kind of wind, picking the right moment to shoot is key. Good luck!

[minaret]

Is your detail gun gravity feed or siphon feed? I probably wouldn't use a siphon feed gun for this, and I only would use a gravity feed if I had limited compressor CFMs. You can buy a decent 1 qt. pressure pot HVLP rig for cheap. Much cheaper than the paint. You'll find you have problems pointing a siphon or gravity gun at the necessary angle to paint a deck without spillage. I would use a remote 2 qt. pot, but that might be a bit much to start.

Cheap 2 qt. pot-

http://cgi.ebay.com/NEW-2-QUART-POT-...-/280647740290


Good gear-
http://www.spraygunworld.com/Informa...PPW/1liter.htm
Amazon.com: Binks Conventional Spray Gun with 1-Qt. Siphon Cup - Model# SV100: Home Improvement

Cheap gear-

Amazon.com: Kawasaki 840762 High Pressure Spray Gun: Home Improvement

Gravity feed-

Amazon.com: Professional Grade 1.7mm HVLP Air Spray Gun with Gun Metal Finish: Home Improvement

Make sure you acquire and use the right tips for topcoating. And study your local laws concerning the use of conventional or HVLP equipment. Remember with the pressure pot you want to run 10-12 lbs. pot pressure and 60 lbs. at the tip. With conventional equipment you can crank the tip pressure to 70 or even higher, which will help you acheive a nice finish with finer atomization, but will also create a huge cloud of overspray, waste some material, and be potentially illegal. Use 20' wide "Sharkskin" to mask all of your boat and any others close by. Make sure you secure it well or it will blow loose and get in your wet paint.

[osirissail]

I concur with Minaret that you should consider getting a HVLP gun. But along with the spray gun comes a compressor and just as important water separator and filters so that the air delivered to the gun is DRY. AwlGrip and water are vicious enemies. I also use an additional dryer cartridge screwed onto the inlet fitting to the HVLP gun.
- - In Florida we only spray between late morning and early afternoon. Never before or after. The reasons are that you have wait until the dew has evaporated in the morning and late afternoon there is not enough time for the paint to set before evening dew start accumulating. There is an additive for AwlGrip called "Accelerator" which will cut the "set time" in half and we use that most all the time. Also there is another additive called "Fish Eye Preventor" that it supposed to help reduce the little circles when the paint sets. I have never had any luck with that stuff so don't use it.
- - What is in the atmosphere when you will be spraying is critical. A lot of chemicals and strange things come floating in with the breeze. We had a devil of a time trying to figure out what what ruinging our paint sprays one day but not another. It turns out when the fishing and scallop fleet was in the harbor their processing loaded the air/breeze with some nasty stuff that ruined our spray that day.