I get so much out of what people post that I thought it might be useful to share this. I sprayed every example I'll mention with a cheap harbor freight or home depot detail or mini gun did a careful job prepping in all cases and followed the directions. I'm not a professional painter, I couldn't play one on tv and I did not stay at a Holiday Inn Express last night... I've painted a few cars and a number of smaller things but there's no question I'm a backyard hack... not a pro... Everything was painted outside, making sure to choose days with conditions indicated in the instructions and low wind to cut down on dust and oversprat. I was very careful with safety and used the right cartridges in the resperator (and kept them in a plastic bag between uses... they absorb vapors from the air over time and lose effectiveness). I do polyurethane chemistry as part of my job and am very partial to those products in general, but there is no doubt that impropper exposure to some isocyanate products can kill you dead or result in cancer or other problems down the road. I'm not including paints that are significantly more toxic or dangereous and require supplied air resperator such as imron or awlgrip... This is all stuff I feel comfortable shooting in the back yard with a filter respirator... You only get one life and set of lungs... at least as far as I know...
This is not based on many years of experience, but just over the past year or so me "testing" things that I read about (some of it on here) and thought was worth trying... yes my hull looks a little splochy if you look close, but I'm going to strip, sand and repaint the lower half this fall anyhow... and since it is black, it's not noticable from a distance...
My experience:
interlux epoxy primekote: I used it on the interior on top of both polyester and epoxy-based resins. great adhesion, sanded well and everything else adhered well to it. As an eepoxy-based primer this is going to give better all around adhesion to glass, resin, gel and older paint then pretty much any other type of paint (other brads of two-part epoxy fit in the same category)
interlux brightsides: I was disappointed in the hardness even after a month or more of curing. It was easy to apply overall, and had good gloss, but it seemed to stratch easily compared to some of the others below. I used black on teh hull and also tried it on one of my outdrives (over primer)
interlux bilgekote: Liked this a lot, it is tough stuff and works as advertised and indicated by other members on the forum. I even painted over it with something else... and when i spilled the wrong combination of fluids on the top coat, the fluids removed the top coat and the bilgekote was apparently untouched.
Rustoleum (high performance protective enamel); I tried nin several colors and several applications. worked fairly well in all, but not as well as the two part paints, nor as glossy as the marine or auto pants, but for under $10 a quart and no undue safety precautions, what do you want. I was disappointed in the gloss of the glass black - it was far less glossy than any of the urethane-based marine or auto paints... not unexpected, but the difference was a lot mroe dramatic than I expcted. I cut corners on painting pullys with it... The difference was so great between that and the pieces I had painted with auto paint that I stripped them and redid them with auto paint. It held up fairly well in the bilge area, but was far less resistent to attack than bilgekote or two part paints. Good bargain, very good adhesion, easy to use, but not the quality of the more specailized and expensive paints I tried.
Rustoleum marine topside paint. much like above, but better gloss. It also seemed to set up harder after several weeks... and was most similar to the interlux brightsides with a ery small amount less gloss and it seemed to be a bit softer even after a fairly long time curing. I tried them both on a part of an outdrive (that wa sbeing used regularly) and on small sections of the hull.
dupont / nason ful-thane 2k urethane: I love this stuff. It works great for engine painting, is not hard to get a very good result with, has outstanding gloss and after full curing for a few weeks, was significantly harder than all but the most expensive paints i tried. It was recommended by my engine builder who also cautioned not to use the corresponding chromabase and clear because gas and oil, solvents would get between the clear and color over time and in their experience it would delaminate. I used fulthane over the appropriate zinc chromate etching primer and can't say enough how much I like the appearance. It is holding up very well on the engine and parts I used it on, even though I've blown a power steeringhose spraying it with ps fluid, have had oil and gass all over it and even hit some of it with paint remover for a few minutes before getting it cleaned off... great stuff period. Note that it is more expensive... say 50 - 100 a quart.. the starburst fireball red I used as a primary engine color looks awesome in the sun and has so far retained all of it's look even after being baked in oil, etc... I've also painted cars and trailers with this stuff and am very pleased with the results. it's also very easy to touch up / blend... and is a good bit harder / more durable than the marine paints listed above. So far it is sticking to the hull as well where I sprayed a small part directly on clean abraided gelcoat.
POR15 hardnose: great gloss, almost as good as the autopaint, recommended for use in water or marine environmenbts, etc... the por15 chemist / tech rep i spoke with said it would be fine for under the waterline as long as not for long periods of use where there was no additional moisture barrier below it and that it might even be fine in long term use... but had not been tested. As advertised, this stuff is tough as it gets. I cut a reasonable sized limb in half with an outdrive i painted with it... it barely even scuffed the paint. Every other paint i;ve done that with, including good auto paint, has chipped or at least scuffed to a significantl degree. I did use the por15 recommended etch prep and although this is expensive paint, it is in my opinion well worth the extra money. I also shot a small piuec of the hull with it directly over clean abraided gelcoat and it seems to be doing very well. As I mentioned, it also has very good gloss.
por15 glisten clear. I love this stuff. It seems to have all of the characteristics of the above hardnose, but it is clear. It was relatively easy to apply and looks great on my polished aluminum imco power flow manifolds as well as on polished brass and steel fittings, etc on engine parts. I used it according to directions and etched the surface with por15 surface prep chsmistry before applying it and let it have a long time to cure before subjecting it to hard use. You can scratch it, but it seems a lot harder to scratch than aluminum, has remained very well adhered to the highly polished manifolds even after exposure to gas, oil and heat... great stuff... although again, it was expensive and the other issue sis that it takes so long to set up completely and harden that it was hard to keep dust free on larger parts. I actually shot my manifolds at work to be sure... it did not pull the lettering fill in I did with nason ful-thane either. where I made runs, I let it cure for a few days and then carefully wetsanded and buffed them out with no problem.
dupont 2k selectclear urethane clear coat. Good clear coat for the money, not as dangereous to apply as awlgrip or imron, gives great gloss, adhered to anything I put it on, has good hardness (a good bit harder / tougher than brightsides if you're thinking about a clear to use over clear gel metalflake). I tried it on the hull as well as on some engine fittings made of brass and aluminum. It is holding up a lot better than rattle can elcheapo clear, but is not nearly as tough or solvent resistant as the por15 glisten product. It does however spray and set-up much faster than the por 15 if you want ot get whatever your painting into use quicker.
ruberized undercoatings: I like this stuff a lot because it is highly water repellent and does a fair amount to dampen sound. I painted the oil pan (over primer and auto paint) with this on my new engine on the recommendation of my engine builder to protect the lower engine from rust where it is exposed to water often in the bilge area. I also coated the sides of the bilge / engine compartment with this stuff and it seems to do a lot to tone down engine noise and vibration noise. The cheap stuff is not worth the dollar. the mid range, Duplicolor brand works fairly well and seems to hold up alone or when coated with paints such as rustoleum or auto paint The 3m professional grade was more expensive, but was worth the extra coin. It is tougher, seems to hold up beter to attack by solvents and did not pull as easily when topcoated by auto paints without a sealer. I wound up coating the sides of the inside of my current project boat with this and will overcoat it with with the same thing I wind up doing the deck with (you guys have talked me out of permanent carpet, I'm going with a rubberized deck coating and then making removable, snapdown carpet, but that's another story).
Hope this is helpful. I'll add others if i think of any or try them. Anyone else with relevant comments or experience on these or similar products is invited to chime in. I'm constantly looking for good ideas and am willing to try new things.
Speaking of trying new things, does anyone know of an elastomeric highly penetrating polyurethane coating for wood? These types of coatings can be formulated to have excellent resistance to water even in constant contact or immersion and if applied to dry wood from solvent should easily give really deep penetration into wood before curing with moisture from the wood to make a very strong water impervious coating that is flexible and significantly thicker / deeper than traditional varnishes or paints. I'm thinking of trying something like this, with an antifungal agent added, to precoat the new wood in my interior... I coated a dry pine 1x2 that i coated with a first try. After soaking in a bucket of water for a month (held down with a brick) it was dry all the way through when I cut it in half... including where the two screws wer run through it. I also tested it on a piece of the new stringers and epoxy adhered to it just fine. This kind of material is an elastomer (means it will flex and come back to original dimensions once cured) coating - cures to a tough skinned flexible almost rubber-like consistency, think of a tough film like the outer skin on a closed cell foam like a swim noodle only a little more flexible.. that is interlaced with wood fibers... the idea is that this will be tough enough to resist surface abrasion, flexible enough not to crack no matter how many times flexed, and flexible / rubbery enough to be self sealing even if someone puts a screw through it into the wood, it will have a good chance at sealing water out...) I made the stuff that I tried. I was curious if anyone knows of a product like this on the market now?
This is not based on many years of experience, but just over the past year or so me "testing" things that I read about (some of it on here) and thought was worth trying... yes my hull looks a little splochy if you look close, but I'm going to strip, sand and repaint the lower half this fall anyhow... and since it is black, it's not noticable from a distance...
My experience:
interlux epoxy primekote: I used it on the interior on top of both polyester and epoxy-based resins. great adhesion, sanded well and everything else adhered well to it. As an eepoxy-based primer this is going to give better all around adhesion to glass, resin, gel and older paint then pretty much any other type of paint (other brads of two-part epoxy fit in the same category)
interlux brightsides: I was disappointed in the hardness even after a month or more of curing. It was easy to apply overall, and had good gloss, but it seemed to stratch easily compared to some of the others below. I used black on teh hull and also tried it on one of my outdrives (over primer)
interlux bilgekote: Liked this a lot, it is tough stuff and works as advertised and indicated by other members on the forum. I even painted over it with something else... and when i spilled the wrong combination of fluids on the top coat, the fluids removed the top coat and the bilgekote was apparently untouched.
Rustoleum (high performance protective enamel); I tried nin several colors and several applications. worked fairly well in all, but not as well as the two part paints, nor as glossy as the marine or auto pants, but for under $10 a quart and no undue safety precautions, what do you want. I was disappointed in the gloss of the glass black - it was far less glossy than any of the urethane-based marine or auto paints... not unexpected, but the difference was a lot mroe dramatic than I expcted. I cut corners on painting pullys with it... The difference was so great between that and the pieces I had painted with auto paint that I stripped them and redid them with auto paint. It held up fairly well in the bilge area, but was far less resistent to attack than bilgekote or two part paints. Good bargain, very good adhesion, easy to use, but not the quality of the more specailized and expensive paints I tried.
Rustoleum marine topside paint. much like above, but better gloss. It also seemed to set up harder after several weeks... and was most similar to the interlux brightsides with a ery small amount less gloss and it seemed to be a bit softer even after a fairly long time curing. I tried them both on a part of an outdrive (that wa sbeing used regularly) and on small sections of the hull.
dupont / nason ful-thane 2k urethane: I love this stuff. It works great for engine painting, is not hard to get a very good result with, has outstanding gloss and after full curing for a few weeks, was significantly harder than all but the most expensive paints i tried. It was recommended by my engine builder who also cautioned not to use the corresponding chromabase and clear because gas and oil, solvents would get between the clear and color over time and in their experience it would delaminate. I used fulthane over the appropriate zinc chromate etching primer and can't say enough how much I like the appearance. It is holding up very well on the engine and parts I used it on, even though I've blown a power steeringhose spraying it with ps fluid, have had oil and gass all over it and even hit some of it with paint remover for a few minutes before getting it cleaned off... great stuff period. Note that it is more expensive... say 50 - 100 a quart.. the starburst fireball red I used as a primary engine color looks awesome in the sun and has so far retained all of it's look even after being baked in oil, etc... I've also painted cars and trailers with this stuff and am very pleased with the results. it's also very easy to touch up / blend... and is a good bit harder / more durable than the marine paints listed above. So far it is sticking to the hull as well where I sprayed a small part directly on clean abraided gelcoat.
POR15 hardnose: great gloss, almost as good as the autopaint, recommended for use in water or marine environmenbts, etc... the por15 chemist / tech rep i spoke with said it would be fine for under the waterline as long as not for long periods of use where there was no additional moisture barrier below it and that it might even be fine in long term use... but had not been tested. As advertised, this stuff is tough as it gets. I cut a reasonable sized limb in half with an outdrive i painted with it... it barely even scuffed the paint. Every other paint i;ve done that with, including good auto paint, has chipped or at least scuffed to a significantl degree. I did use the por15 recommended etch prep and although this is expensive paint, it is in my opinion well worth the extra money. I also shot a small piuec of the hull with it directly over clean abraided gelcoat and it seems to be doing very well. As I mentioned, it also has very good gloss.
por15 glisten clear. I love this stuff. It seems to have all of the characteristics of the above hardnose, but it is clear. It was relatively easy to apply and looks great on my polished aluminum imco power flow manifolds as well as on polished brass and steel fittings, etc on engine parts. I used it according to directions and etched the surface with por15 surface prep chsmistry before applying it and let it have a long time to cure before subjecting it to hard use. You can scratch it, but it seems a lot harder to scratch than aluminum, has remained very well adhered to the highly polished manifolds even after exposure to gas, oil and heat... great stuff... although again, it was expensive and the other issue sis that it takes so long to set up completely and harden that it was hard to keep dust free on larger parts. I actually shot my manifolds at work to be sure... it did not pull the lettering fill in I did with nason ful-thane either. where I made runs, I let it cure for a few days and then carefully wetsanded and buffed them out with no problem.
dupont 2k selectclear urethane clear coat. Good clear coat for the money, not as dangereous to apply as awlgrip or imron, gives great gloss, adhered to anything I put it on, has good hardness (a good bit harder / tougher than brightsides if you're thinking about a clear to use over clear gel metalflake). I tried it on the hull as well as on some engine fittings made of brass and aluminum. It is holding up a lot better than rattle can elcheapo clear, but is not nearly as tough or solvent resistant as the por15 glisten product. It does however spray and set-up much faster than the por 15 if you want ot get whatever your painting into use quicker.
ruberized undercoatings: I like this stuff a lot because it is highly water repellent and does a fair amount to dampen sound. I painted the oil pan (over primer and auto paint) with this on my new engine on the recommendation of my engine builder to protect the lower engine from rust where it is exposed to water often in the bilge area. I also coated the sides of the bilge / engine compartment with this stuff and it seems to do a lot to tone down engine noise and vibration noise. The cheap stuff is not worth the dollar. the mid range, Duplicolor brand works fairly well and seems to hold up alone or when coated with paints such as rustoleum or auto paint The 3m professional grade was more expensive, but was worth the extra coin. It is tougher, seems to hold up beter to attack by solvents and did not pull as easily when topcoated by auto paints without a sealer. I wound up coating the sides of the inside of my current project boat with this and will overcoat it with with the same thing I wind up doing the deck with (you guys have talked me out of permanent carpet, I'm going with a rubberized deck coating and then making removable, snapdown carpet, but that's another story).
Hope this is helpful. I'll add others if i think of any or try them. Anyone else with relevant comments or experience on these or similar products is invited to chime in. I'm constantly looking for good ideas and am willing to try new things.
Speaking of trying new things, does anyone know of an elastomeric highly penetrating polyurethane coating for wood? These types of coatings can be formulated to have excellent resistance to water even in constant contact or immersion and if applied to dry wood from solvent should easily give really deep penetration into wood before curing with moisture from the wood to make a very strong water impervious coating that is flexible and significantly thicker / deeper than traditional varnishes or paints. I'm thinking of trying something like this, with an antifungal agent added, to precoat the new wood in my interior... I coated a dry pine 1x2 that i coated with a first try. After soaking in a bucket of water for a month (held down with a brick) it was dry all the way through when I cut it in half... including where the two screws wer run through it. I also tested it on a piece of the new stringers and epoxy adhered to it just fine. This kind of material is an elastomer (means it will flex and come back to original dimensions once cured) coating - cures to a tough skinned flexible almost rubber-like consistency, think of a tough film like the outer skin on a closed cell foam like a swim noodle only a little more flexible.. that is interlaced with wood fibers... the idea is that this will be tough enough to resist surface abrasion, flexible enough not to crack no matter how many times flexed, and flexible / rubbery enough to be self sealing even if someone puts a screw through it into the wood, it will have a good chance at sealing water out...) I made the stuff that I tried. I was curious if anyone knows of a product like this on the market now?
