what went wrong? painted over epox:.disaster

[emergpa1]

I sealed my plywood bulkheads with three coats of epoxy, then sanded, then primed with general purpose primer, then coated with two coats of " oil based porch paint. Now i have a yellow film over the surface of the paint, and, as the photo shows, the paint can be marred easly. Now after all that cutting, fitting, sanding, sealing, painting, it all has to be done again. correctly this time, i hope
Does anyone know the right way to seal wood with epoxy, then paint over it?
keith

 

[Shoaldrafter]

Epoxy requires special primers

Keith,

When ever I use epoxy and plan to paint it, I use a primer designed for epoxy. Yes, there are special epoxy primers for indoor use, outdoor use and marine uses.:naughty:

X-I-M Products makes two such products that I have uses with good results. One is called UMA bonder, the other X-I-M primer.
http://www.ximbonder.com/
And there are other companies making specialty primers.

For marine applications, Blue Water Paints makes marine epoxy primers:
(http://www.bluewatermarinepaint.com/yachtprimers.html)

I am not a chemist but I think that it has to do with bonding to plastic. Also,
It helps to apply the primer as soon as epoxy is hard to touch, say in about two hours.

Ed K
26

I sealed my plywood bulkheads with three coats of epoxy, then sanded, then primed with general purpose primer, then coated with two coats of " oil based porch paint. Now i have a yellow film over the surface of the paint, and, as the photo shows, the paint can be marred easly. Now after all that cutting, fitting, sanding, sealing, painting, it all has to be done again. correctly this time, i hope
Does anyone know the right way to seal wood with epoxy, then paint over it?
keith

 

[emergpa1]

Keith,

When ever I use epoxy and plan to paint it, I use a primer designed for epoxy. Yes, there are special epoxy primers for indoor use, outdoor use and marine uses.:naughty:

X-I-M Products makes two such products that I have uses with good results. One is called UMA bonder, the other X-I-M primer.
http://www.ximbonder.com/
And there are other companies making specialty primers.

For marine applications, Blue Water Paints makes marine epoxy primers:
(http://www.bluewatermarinepaint.com/yachtprimers.html)

I am not a chemist but I think that it has to do with bonding to plastic. Also,
It helps to apply the primer as soon as epoxy is hard to touch, say in about two hours.

Ed K
26

Thanks Ed, Since I am planning to use one part LPU paint ( Brightside) to paint my repairs, and since my repairs are with clear epoxy, i researched and ordered the recommended solvent for prepping the surface, then an "epoxy primecoat" for the primer, then the on part interlux brightside topkote paint. I wonder if i would do the same over wood. I guess that would be the correct procedure, but i would probably want to use the LPU to paint the bulkhead, instead of the oil based "porch paint" that i bought. If it were not so danged hot here in GA, i would go to the storage shed and see what kind of paint this "porch paint" is.
Here is what the top of 'My Girl' Looks like now. Inside of the blue tape is where i am going to paint the repairs. I intend to outline the area with a 2 or three inch band of tan kiwi Non skid, then the inside will be a light greyish beige. I hope that the balance of having the mast area and the two chainplate areas painted the same scheme will make it look OK.
I am going to restore the inside to the original floor plan, with the exception of the cabin walls, and the finish.
what do you guys think?

 

[Maine Sail]

I sealed my plywood bulkheads with three coats of epoxy, then sanded, then primed with general purpose primer, then coated with two coats of " oil based porch paint. Now i have a yellow film over the surface of the paint, and, as the photo shows, the paint can be marred easly. Now after all that cutting, fitting, sanding, sealing, painting, it all has to be done again. correctly this time, i hope
Does anyone know the right way to seal wood with epoxy, then paint over it?
keith

I have seen similar results when the amine blush was not properly washed and cleaned away. Sanding alone does not always remove the blush in my experience. That being said a primer intended for epoxy is probably going to be your best choice.

 

[emergpa1]

I have seen similar results when the amine blush was not properly washed and cleaned away. Sanding alone does not remove the blush. That being said a primer intended for epoxy is probably going to be your best choice.

agree, theere is a yellow sticky somehting leache throug th to top surface of the paintl lllit had to have been eopoxy. No dowbt about it. I hafe ben dong paint and finish work for years and have never had this problem until now. It has to be the incompatability of the amix epxoy and the priber and oil base poarch paint.
so how de we get this epoxy blush off.
pardon the spellling please...thaniks

 

[Retics&Bassets]

This may sound off the wall but try a little bleach on the finish in a test spot before you start all over again. I've rescued a lot of bad finishes with a little bleach. It'll raise the grain but you can sand that back down again. I don't know what to expect with the epoxy, but it sounds like you have nothing to use.

 

[emergpa1]

agree, theere is a yellow sticky somehting leache throug th to top surface of the paintl lllit had to have been eopoxy. No dowbt about it. I hafe ben dong paint and finish work for years and have never had this problem until now. It has to be the incompatability of the amix epxoy and the priber and oil base poarch paint.
so how de we get this epoxy blush off.
pardon the spellling please...thaniks

Ha, the above was s/p one ambien. You see, I work swing shifts, and if i want to go to bed at a normal time with the family on days off I have to take an ambien. Rarely i will take my laptop to bed with my for a few minutes to catch up on the news. The above is what happens when the hypnotic kicks in before I finish. I do not remember that post, though I did have a queer feeling that I may have done something like that when I awoke this morning.
Interesting effect.

 

[Shoaldrafter]

so how de we get this epoxy blush off?

This may sound off the wall but try a little bleach on the finish in a test spot before you start all over again. I've rescued a lot of bad finishes with a little bleach. It'll raise the grain but you can sand that back down again. I don't know what to expect with the epoxy, but it sounds like you have nothing to use.

Keith asked, "so how de we get this epoxy blush off?"

'Acetone'

The same stuff you are supposed to use between layers of epoxy to prepare for next layer.

Wear respirator indoors and use solvent gloves, not your medical gloves.

Also, have a drink to replace your electrolytes from all the sweating.

Ed K
26

 

[emergpa1]

I have seen similar results when the amine blush was not properly washed and cleaned away. Sanding alone does not remove the blush. That being said a primer intended for epoxy is probably going to be your best choice.

Thanks Maine Sail,
I think it is the blush also, I didn't wash the bulkheads like I should have. I had read that I should, but didn't remember until after I had applied the primer. Some things I have to learn the hard way.
I am glad I disovered that on the plywood bulkheads instead of after painting the deck areas. Since I have done the deck repairs with epoxy, I wouldn't want to discover that mistake then.
What do ya'll think about the idea for painting the repairs? Has anyone done anything similar, instead of trying to match the gelcoat color, texture etc. Doing the gelcoat just seemed to complicated. (even though I did read about the way you can make a mold for the nonskid, etc)
You guys are always helpful.
keith

 

[Maine Sail]

Actually

Actually West ystems advises against the use of solvents to remove amine blush. Below are the instructions from the West System web site:

"Amine blush can clog sandpaper and inhibit subsequent bonding, but this inert substance can easily be removed.

To remove the blush, wash the surface with clean water (not solvent) and an abrasive pad, such as Scotch-brite(TM) 7447 General Purpose Hand Pads. Dry the surface with paper towels to remove the dissolved blush before it dries on the surface. Sand any remaining glossy areas with 80-grit sandpaper."

 

[emergpa1]

Keith asked, "so how de we get this epoxy blush off?"

'Acetone'

The same stuff you are supposed to use between layers of epoxy to prepare for next layer.

Wear respirator indoors and use solvent gloves, not your medical gloves.

Also, have a drink to replace your electrolytes from all the sweating.

Ed K
26

For the bulkheads, the paint is just too soft. It seems that the epoxy bleeding through made the paint soft, it is easily abraided with fingernails.
I promise I wasn't drinking when I did the work. Nor had I taken an Ambien!
We are going to a place in Austel, Ga, to look at some teak or hickory plywood. I may use that instead of painting.
Two steps forward, and one step back, but I am learning alot.

 

[emergpa1]

Actually West ystems advises against the use of solvents to remove amine blush. Below are the instructions from the West System web site:

"Amine blush can clog sandpaper and inhibit subsequent bonding, but this inert substance can easily be removed.

To remove the blush, wash the surface with clean water (not solvent) and an abrasive pad, such as Scotch-brite(TM) 7447 General Purpose Hand Pads. Dry the surface with paper towels to remove the dissolved blush before it dries on the surface. Sand any remaining glossy areas with 80-grit sandpaper."

thats what i was thinking too, when i read eds post, but I don't like to disagree with ed, he usually knows the right way...in fact, if he says acetone, then probably it would work too. But i will use water. I intended to do that on the bulkheads, but forgot.

 

[Shoaldrafter]

thats what i was thinking too, when i read eds post, but I don't like to disagree with ed, he usually knows the right way...in fact, if he says acetone, then probably it would work too. But i will use water. I intended to do that on the bulkheads, but forgot.

Keith,

Amine Blush is a by-product of epoxy curing.

Some epoxies have little and some have a lot.

Chemically it changes the structure of epoxies and is said to be a water based solvent.

Therefore, Maine sail is correct is saying that washing with water will remove the blush which is water soluble. After washing the sanding improves mechanical adhesion to epoxy.

Others say use ammonia to wash surface with.

Actual boat yards use a solvent like acetone or alcohol based on experience. Keep in mind that acetone changes the chemical nature of the surface of cured epoxy resulting in a softer sticky surface at often allows the next layer to adhere better. This is the purpose of sanding, increase mechanical adhesion.

If you put second layer of epoxy or other epoxy paint on before epoxy cures you generally do not need this step of cleaning.

Once epoxy has cured, you need to prepare surface in accordance with that manufacturers recommended procedure. That information can usually be read on can or calling their customer service.

In the repair yards it is generally said 'cheaper epoxies blush more'. This is often a point some manufacturers/brands use against other brands. However, epoxies that blush may be more flexible than non blushing epoxies and better suited for certain applications.

So wash, sand and get surface clean. Again, use appropriate safety gear.

Ed K

 

[appleman]

Keith, I have the answer to your problems. Your workshop is far to neat and tidy. How can you possibly work in a place that you can find things in and you don't have to be a contortionist to get from one side to the other?:dance:

 

[emergpa1]

Ha, the key was that workbench I built from plans in "the family handyman". It has a build in miter (chop) saw, fold out tabletop, and even a table saw module that slides in under the bench, and has a fold out out-feed table on it.
Can you see the map of florida on the door to the right. If you look close, you can see places circled that i want to trailer the boat.
keith