A few things to consider when painting......

[MacGyver]

 
Today at work we triple teamed a boat sand job. So far we have a bunch of hours in it and am not done yet......
Why?

Well, this is a issue we see every so often. I have no guesses as to who did the previous work, I just know it wasn't us. But as I was sanding thru layer after layer of paint, I realized, this may be something people don't think about...... I mean why would you just glob layer after layer on and do a rough job....... it is so easy to do it correctly.

I will talk about bottom paint... but this can apply to all paints for the most part.
Bottom paint is there to protect the bottom from growth, and is made to come back off, it is a sacrificial layer. And like every other paint used anywhere, it is also used to add a certain look to the boat/item. There is also a primer, a "barrier coat" that is usually Epoxy based, and is used to seal the bottom before the application of the sacrificial layer or bottom paint.

Different paints do different things, like ablative for instance, is self shedding. As one layer is scrubbed off or worn off, a new layer is left behind. Eventually, a fragment of the paint is left and it is time to renew the surface. You wouldnt want to repair or paint over ablative as it would end up shedding it off.....

Other paints work in a similar manner, but some just build up, and eventually lose their ability to fight off the growth. They must be sanded or washed down then painted on top of it.

Each paint, has a ability to hold so much weight. We call it "bite" at our marina. As you layer paint on itself, you are adding weight. Eventually this weight can have adverse affects on its "Bite". You will get flaking or chipping as it loses its "bite" and it could possibly break down all the way to the original surface.

This boat we are working on has several things going on. We have from the outer most surface going down to the gelcoat: Blue ablative, Red ablative, patchy barrier coat (2000), Watertite filler over Red ablative, 2000 over Red ablative. 5200 or similar rubbery caulk. And a fairing filler over Shiny Gelcoat.
These layers will tell a story. They painted the boat Red, at some point, some damages were found, so repairs right over the issues were made, and barrier coated spots, then red painted again.
There was yet another defined layer of repair work done with yet another paint job of red.
Then someone changed the color to Blue......

A few notes:
A solid surface is a great surface to adhere to. No defects, etc. Get rid of all shine. You need to achieve proper "bite".
You are looking for a MECHANICAL BOND. Dont trust "sand in a can" as you cant see what is there when it is done.
Properly prepared surface is like a insurance policy, you are giving it the best possible chance to succeed.

Do not paint over old paints. Paints have a life to them. They really will only last so long... they dry out chemically. Years ago, manufacturers used to say you can paint over this paint or that, no problem... well, they dont get into the "Bite" issues..... they assume people know about this. The more weight you add (which to us doesnt seem like much but it is on a micro level) the less ability the old paint has as it ages to keep itself adhered to the surface. As it dries out, the layers delaminate, and you get issues. These issues lead to a direct line for penetration of the elements down to the surface you are trying to protect, ultimately defeating the intended purpose.

Lastly, repairs made to anything over sacrificial layers is self defeating..... fillers and stuff are meant to adhere better than paints, since their job is to repair, not protect. You will just be throwing your money away....... If you want to do that, just send it to me
By starting from the beginning surface, one can ensure the proper steps to having a complete and long lasting job. This benefits you as a current boat owner all the way through the sale of the boat.

How can I say that with certainty? Well, the current job is so big and as a part of the sale, we are to repair all the issues on the bottom, and the paint job is one of them. This price comes off of the sale price for the original owner. BIG MONEY.
Over time, this would have been money in the pocket for him, had everything been done properly.

Lastly, I want to say, I am here to help people the best I can. I enjoy boats, and take a EXTREME pride in the work I do. I have developed a few processes that our reps have taken back to the company and implemented. I am proud to set standards and live by them.
I never want to see a job come back to our marina. I feel the same way when I work on things at home. And that also keeps the wife off my back when I do actually finish things.......         my wifes face when I do ---> 

That said, EVERYONE has their own way or doing things. Some of what I do is overkill, but it is a cheap insurance policy for me and my employer, which in turn is a payoff for the customer. I am just sharing that with you so you can produce the same results.

I plan to post some more informative posts in the future, and I hope that as you read this, it helps to make your repairs and work more efficient and long lasting.

Less work means more FUN (sailing!)
Mac

[skip1930]

I agree; Industrial Paint Finishing has been in our military family since I was in kid in grade school and dad had two partners that started The Spra-Con Company.

1~The paint job will be no better than what is underneath it.

2~Surface prep is 99.9% of the total job.

3~Cleanliness is everything.

When chrome metal bumpers went away and was replaced by RIM and rubber over stylized Styrofoam shapes new pretreatment and paints were developed and new problems crept in resulting in mis~painted soft rubber parts. Parts where too soft to be traditionally sand blasted or chemically stripped without profiling, [flating out the molded in curves].

To de-paint soft parts efficiently and quickly at the normal rate [equal to Black Bueaty sand blasting on steel] of 1-1/2 square foot per minute the following came to be. For more info Goggle 'ARMEX® Cleaning and Coating Removal Systems'.

1~Church and Dwight Chemical reformulated Arm and Hammer baking soda into a crystalline structure having sharp facets that abrade the surface overlays down to the original substrates without profiling the soft substrate. Read Gel Coat/Fiberglass.

2~A Schmidt pressurized blast pot is needed to deliver the blast media with a copious amount of air.

3~A Sullair Air Compressor of 500 scmf [standard cubic foot per minute] diesel powered compressor can handle two manual ceramic blast nozzles for de-painting.

The blast media de-paints but also fractures into dust and I use it with a 1/3 of a gallon of water per minute to hold the dust down. The dust will raise the pH and kill off the wife's flowers where ever the dust settles. Good thing is the 'dust' dissolves in water, leaving behind the paint to be scooped up and disposed of. Also works on degreasing semi truck fifth wheels, ect.

Two demonstrations that I attended at Binks in Chicago; In a business suit;
I de-painted the clear coat off the tail gate of a new zero milage Ford F series P-up truck. Stopping at the color coat.
Then continuing removing the color down to the Electrodeposition applied epoxy primer and stopped.
Then removed the primer down to the bare steel, rinsed and air dried.

Did the same thing to a 1956 fiberglass removable top [with the head liner pulled out] on the boss's Thunderbird. Took the black paint off, the primer off, left a polished gel coat and even polished the round chrome port holes and did not harm the rubber window gaskets or profile the glass.

With this success I rented what I needed and de-painted a dozen glaze curing ovens for Eko-Glaco in a South Suburb of Chicago.

This works great and there is no reason it won't work de-painting any bottom of any Com-Pac Yacht.

Side Bar: Eko-Glaco stamps out and leases commercial 'bread and bun pans' to bakeries who are suppliers to business's like MacDonald's, and Wendy's to the tune of $350,000,000 a year. The pans need a tune up every once in a while and come back for stamping after which the nonstick glaze is chemically washed off, rinsed, dried, reapplied, flashed off, and the solvents baked out, collected and thermally destroyed in the 23 glazing systems my company built and erected in seven states, all achieved the required EPA discharge compliance certificate.

skip.
A general gist of an Electrodeposition paint tank out of the 1950's. Developed in Germany and first used for the Ford Gallexy 500 rocker panels.

[Ted]

Macgyver,

I have been poking around on this website for quite a while now reading the various philosophies about paint. Quite a bit of info.

I would be curious to know your recommendation for my situation. I recently purchased a '90 CP19 that was originally sitting on a boat lift over by Clearwater. The PO then got it and put it in the saltwater at a marina by Miami, where it sat for about 2.5 years. He paid the marina to scrape the hull (diver) once a month and it was scraped just before I picked her up. When I got it home I took out a brush and started to scrub. Most of the blue ablative paint was coming off, with some rough spots where fragments of the barnacles were still clinging. I can't have a boat in my driveway overnight (semi-communist HOA) so I put her in the lake. I would like to haul her out in the next two weeks and do up the bottom.

My situation is that the boat will sit in freshwater most of the time. I fear blistering. I had a boat once that developed bad blistering and know that freshwater is a contributor. I assume that I will put some sort of ablative on her. What would you recommend for a base coat and ablative? I am not wanting to spend hundreds on paint, if possible.

Thanks for sharing your expertise on this website.

[MacGyver]

No problem Ted, Thanks for taking the time to read my posts, as I know they can be quite lengthy!

I will start with that I am not totally familiar with the barnacle issue, so that is a gray area, but since that is not necessarily needing a answer, I will start with this:

I recommend using Interlux 2000 to do the boat for starters, it is a "primer" known as a barrier coat. It is super user friendly, unlike many other products.
For your boat you need 2 gallons, and I know this because that is what I am doing to my boat now.
Several coats and max time between coats is like 6 months! So easily worked into time schedules. WEAR A RESPIRATOR!  I have not been doing that for years and this year it really got to me..... it was my stupid ignorance that I did that......

Next, I would use Interlux Micron CSC. You will need a Gallon. (actually you need about 3 quarts, but a gallon is the better cost and the extra can be applied or kept for touch up down the road)
It is a ablative. Perfect for trailer and leaving it in the water. If the boat had to be left on shore, No Problem! it is not affected by the UV and all that like most other paints. Over time if left out a long time like anything else it will degrade, but that is to be expected.

2000 will cost about 100 dollars a gallon, Micron CSC is any where from 180 a gallon to 280 a gallon. Price DEFENDER.COM.  They seem to be the best overall on pricing.

The 2000 will guard against blistering. several coats are applied to achieve a thick coating to keep water from infiltrating the hull. The hull can be prepped by using 40 grit sand paper and using 80 grit at the water line being careful not to go above the water line with the scratches. Tape can be used to keep someone from sanding above the water line, or taping then hand sanding it to ensure mechanical adhesion is highly recommended since this is the relied on coating for adhesion of the "money coating".

Micron is a bit more pricey, but for ablative and its ability to work with whatever life throws at you is why I plan to use it and recommend it.
Some of the others on the market really jump the price up nearly to 400 a gallon....

Between the 2000 and the Micron, no sanding is needed if you wait 3 hours to coat the micron on top of the last coat of 2000. !!!Ensure you have a complete coat of 2000 before you coat the micron so you get a CHEMICAL bond!!!!

I recommend RED MOHAIR roller covers for 2000. The do cost a bit more than some other rollers, but they dont shred apart during use due to the catalyst acting on the glue holding the roller together.
Paint brush over foam brush for the same reason.

use the same with Micron for a nice looking paint job.

Lastly, I plan to finish my boat sometime, and was going to show how to in a video coat a boat and make the job look seamless, meaning it is extremely hard to tell that I didnt just magically hover the boat in the air and paint it.   I end up painting with no seam lines that are easily found, and I hope to pass that knowledge on to those that wish to know.

I hope this helps! Lot to read and if I missed something please by all means ask and I will let you know! 

Thanks,
Mac

[Bob23]

Mac:
 Thanks for sharing the info gathered by years of experience. Here on the East coast of NJ, I sail in salt water so barnacles and slime growth are our main concern. The prevailing thought for bottom work is thus: An epoxy barrier coat such as Interprotect, actually 3 coats. While the last is still tacky, apply a hard bottom paint (same manufacturer) and let dry. Over that, a contrasting color ablative- the obvious reason being that one can see when the ablative is getting thin because of the color contrast. I personally have had great success with Hydrocoat water based bottom paint from Pettit. I applied one coat to the existing bottom paint the first summer I had my 23. After haulout, nary a barnacle in sight!
  Next spring, wondering about recoat, I contacted the Pettit rep and asked if I should recoat. His response was "if there is paint on the bottom, it will still work; no reason to recoat." So I touched it up, sailed all summer and upon fall haulout, again- no growth. I got 3 seasons out of one coat. Of course, I did touch it up before each spring splash.
  Feeling guilty, before the 4th seasons splash, I recoated the boat. Fall haulout, I was surprised to see some growth where I'd had none in the first three summers. Maybe, as you explained, there was just too much paint on the boat. Subsequent falls have yeilded the same result. Makes sense about adding weight to the coatings.
  This winter or spring, I plan to remove all the bottom paint, barrier coat it and proceed as above. What's your opinion about Hydrocoat? Have they changed the formula over the years because my earlier experience was great while recently, the paint seems to fail? For ease of application, it can't be beat and because it dries quickly, when she's sitting in the travel lift slings, I get to touch up the keel while the crew is eating lunch.
  Thanks for your input,
bob23
I think this photo is just before season 3 launch:

[skip1930]

Macgyver and Ted, Since Ted appears to be living in a highly industrialized and commercially viable area maybe a few phone calls to local sand blasters could fine an outfit that would Soda Blast with baking soda, the hull from the waterline on down.

That way, "The hull can be prepped by using 40 grit sand paper and using 80 grit at the water line..." could be avoided.

The CP-19 can sit by itself on a leveled trailer rollers if a strap is fitted to each stern cleat and ratcheted down to the loops on the trailer.
Then the hull bunks, one side at a time, can be lowered for blasting by them and later painted by you. The bow is snugly fitted into the vee block at the winch.

Soda blasting is no faster then sand blasting, about 1-1/2 square foot per minute per layer and leaves a very nice finish on fiberglass. Ready to be washed, dried, primed and painted.

skip.

[MacGyver]

2 things before I answer more questions:
I also remembered a place called Jamestown Distributors as a paint go to place. They are online as well as Defender.
Secondly, we pressure wash the boat hard after sanding in order to get all the dust off, ensuring a solid paint job. After I implemented this step, it seems to have really helped out over the years to ensure a long lasting paint job.

Bob23, I have had some luck with Petit products mainly because they put a lot of Cuporus Oxide into their paints. That stuff is toxic but is what does the job of fending off the growth, a necessary evil I suppose.
That Hydrocoat is a water based paint, so easier to use, and a ablative, which is also good. Without seeing it close up it is hard to tell what exactly is going on, but From what you have said I have to think that it is a failure in the paints poisons that is causing it to fail at its job.

That said, it would not be a surprise to me if they changed their formulation, as I know Interlux has had to thanks to our EPA and its ability to continue to stir the pot. Not saying changes arent needed maybe, but I can tell you that PETIT TRINIDAD is some really good paint, really expensive, and REALLY poisonous, its fumes from down our parking lot have made us sick from time to time. The EPA has not cracked down on that......

IF you do take the paint off, and sand that barrier coating, I would add a few coats to "renew" the barrier coat (2000)  The Barrier coat is unaffected by the multiple coats weighing it down and breaking the bonds affect due to it being a epoxy coating. We usually put 5 to 7 coats on a boat.
Paint however is only as good as its ability to bond to itself, and that is why it is a great idea to do exactly as the manufacturer says and also do not stretch the paint thin as you go to save a buck. By not putting a coat on as thick as is needed, essentially you are keeping the 2nd coat from resolventizing (I think I coined that word...)  the first coat and bonding properly before curing.

I hope I answered your question as well as I can. Sometimes paint issues are a hard one without seeing totally what is going on.

Skip1930, I have not ever seen or had soda blasting done, and not sure what the finished product would leave as far as a surface. Ted, that is something you could look into, but I would be very mindful of the finished and ready for paint surface you were left with.
Either way, be sure to pressure wash or soapy (DAWN) water scrub and hose down the bottom and let dry before painting to ensure a clean surface to adhere too.

Mac

[skip1930]

" we pressure wash the boat hard after sanding in order to get all the dust off, ensuring a solid paint job. After I implemented this step, it seems to have really helped out over the years to ensure a long lasting paint job. "

Yep, not possible to paint over dust and loose material.

As for the Schmidt Pressurized blast pot, the 500 scfm compressor, the 17 bags of Arm and Hammer/Church and Dwight baking soda blast media stacked in the back of a pick-up truck, and the time to blast, what is left is the smoothest, cleanest gel coat ever. Of course this was made and developed for the automobile industry to de-paint two and three componet paint compounds on all those 'plastic' body parts. GM in about 1972 started it and now it's world wide.

Looks like the hull was just popped out of the mold. The really neat thing about this is the backing soda blast media dissolves in water, leaving only the blasted off material on the ground waiting to be broomed up and tossed.

skip.

[brackish]

adding a recommendation for bottom paints, based on the Practical Sailor two year in water tests, FL and CT, I bought Blue Water Marine Copper Shield SCX to do my bottom.  After the first season, I took the boat into the shallows, and just lightly wiped off a little slime, ready to go again.  I think it may be possible to get three seasons out of it, but time will tell. I did not remove the old, but changed colors to get an ablative indicator. Pressure wash and light sand so as not to disturb the barrier coat or remove all of the old color.   It is currently $165/gallon. The paint was both a top performer and best value by PS and I tend to trust their comprehensive tests.

did it on the trailer.  Ouch, not sure I would do that again.  



As I recall, a gallon put me just short of having two full coats on a 23.  I ended up with the second coat from the waterline down but not quite getting all of the keel.  Next time I'll order a gallon and a quart.

I'm year round in the fresh, not sure how it would do in the salt.  The PS tests, both north and south, were in the salt.

My last boat had a bolt on lead keel.  I found sandblasting the only safe and practical way to remove growth and prep for new paint.  There was a fellow who hauled his blast equipment from yard to yard and would blast your keel for $50.  Money well spent.  He would also do a full blast on a blistered boat in order to open up the blisters and start the dryout process.  Obviously his pricing was based on the square footage, but still a bargain compared to the alternative.  This of course was a complete start over on a badly blistered boat, if just a few blisters here and there, better opened up with a grinder.

[Ted]

I ordered my paint from Jamestown. That hurt a bit - that stuff is spendy.

Will keep you posted....

[Bob23]

Brack:
   Were you lowering one bunk at a time while strapping the opposite side of the boat to the trailer? Great looking boat...although I do admit to bias. I used to be a PS subscriber but had to let it lapse. I was just getting too many sailing mags. I still have my old copies and did appreciate the thoroghness of thier tests. I may have to check out Blue Water but I do like the water based bottom paints. Not near as toxic to apply.
bob23

[brackish]

Brack:
   Were you lowering one bunk at a time while strapping the opposite side of the boat to the trailer? Great looking boat...although I do admit to bias. I used to be a PS subscriber but had to let it lapse. I was just getting too many sailing mags. I still have my old copies and did appreciate the thoroghness of thier tests. I may have to check out Blue Water but I do like the water based bottom paints. Not near as toxic to apply.
bob23

Bob, that was the plan.  In the picture I had finished all but under the bunks and keel rollers and I was ready to drop the bunks.  When I started turning the first hex head machine screw that locks the bunks in place it twisted off with very little pressure.  So I went to plan B, put a couple of jacks under the keel and lifted it up enough to get under the bunks and keel rollers.  One of these days I'll have to easy out that broken bolt.

[Ted]

SO... here is the update. The paint arrived from Jamestown and the admiral and I tackled the job this past week. I took off a day from work and Monday was a holiday at our office, so...

To paint the boat I put a floor jack under the keel and place a board between the jack and the boat. I then put loose straps around the boat - a total of four straps (you can't see them all in the picture, but there are two forward and two aft). Jacking the boat up a few inches, I was able to center it by hand and tighten the straps down. Then, I simply unscrewed the holders for the bunk boards (don't worry - I will be replacing all the bunk boards soon: that is how I got the boat). This held up for three days and when I was finished, I only had a small spot on the bottom of the keel to return to in order to add more paint. The trailer actually rose a bit but I still had clearance under two of the three rollers to get a brush.



(This pic is after the first coat of ablative. It's still wet so it might not look uniform, but when it was done it sure was pretty!)

I spent a whole day sanding and prepping the bottom. It was not fun. The PO had kept the boat in saltwater and the little critters down there took a fair amount of scraping to loosen up. I used a sander and 80 grit paper after the scraping and that went a bit easier. I took three ibuprofins and when to bed. The next morning we started with the Interlux. My wife likes to paint so the two of us knocked out a coat about every two hours or so until we had almost all of the paint used up. By this time our shoulders were aching! Painting from the ground up over a couple days can tire one out. The ablative was next and two smooth coats later we were done. That was the easy part.

The boat is on the hard for a week or two and then we will put her back in the lake!

[MacGyver]

Ted, Great job, looks good!

I am lucky that I have lifts at my disposal to use to finish my job, but our lifts may all be in use to get all the work done this year...... I might just have to utilize your way to finish the work on mine so I dont have to wait in line so to speak to get mine done. 

Wife is really wanting the boat in ASAP.....

Great job!
Mac