H-e-l-p!!! Please!!!!!

Hi guys,

I'm new to this forum, but it looks like it might be my best place to help solve my problem. I've search high and low on the internet, and everyone is telling you how to apply stain and polyurethane but, no one seems to be explaining what causes poly to look like mine is looking. I will attach some pics.

I don't consider myself a "professional finisher" by no means, however, I've always had a knack for working with wood and finishes, but I have NEVER run into a situation like I'm dealing with now. I'm customizing a new Jon boat that I bought back in April of 2012. It's a long story so I give you the short version. I purchased an HVLP Sprayer from Rockler Wood Working. I understand Harbor Freight sells one exactly like mine. I think it's a Chicago Electric???

At any rate, last year I used a sheet of Arauco plywood cut to fit for the floor in my boat. After sanding, I used this HVLP sprayer to shoot Minwax Helmsman Polyurethane, straight out of the can, no thinning at all, and I got a beautiful finish! I have to do all my spraying outside, no paint room, so I'm out in the sun and wind. Same last spring when I did the floor, and like I said, it turned out really nice!

So far this spring, I've had to take a putty knife and scrape the finish back off of all of this wood....TWICE...sanded back down to bare wood, took my gun apart....AGAIN....just to double check for cleanliness, no dirt, nothing plugged, changed the nozzle and needle....and I'm still getting the same effect!!! Also using a brand new can of the poly, so it hasn't been froze, or gotten old. Guys........I'm about to completely lose my mind! After this last coat, I came totally....unglued!!!!!!

Looking at this finish, it reminds me of what you might see if I were using a large two stage air compressor with no filter on it and it was spurting out little spots of oil with the poly, however......that is not the case! The three times that I've shot this poly so far this year, the temps were mid 60's to mid 70's, and some wind, full sunshine. Some of this wood, the final finish isn't really that important to me because it's going to get carpet glued to it. But the two pieces that are stained, I want a top-notch finish on them.

Note: I've tried spraying the poly on so "thin" that it barely covered the wood, and I still get the same effect. It's almost like there is some sort of oil in or on the wood, which to my knowledge....is impossible! It's almost like it drying on top before it can flow and level, but truthfully...I don't think that's it either!

But, regardless of whether or not some of the wood is going to get carpet glued to it or not....I need to find out what in the heck is causing that poly to act the way it is and........I can not find any kind of logical reason for it. At least, not to my somewhat limited knowledge of finishing. Any help, knowledge or information on this matter will be GREATLY appreciated!!!!
Please look closely at the pics.

Thanks in advance!

Dennis

 

Welcome to the forums.

I'm not the pro here but it looks like it's on too thick.

Hang tight.... there are some great woodworking and finishing guys on the board that should be able to help you.

 

Thanks PJmax!

Like I said, I've tried to spray that poly on so thin that it barely covered the wood and it seemed to still be giving me the same effect. I will admit that looking at the pics, it does look like it's on there pretty thick, but "I think" that's because of the poly *gathering* the way it is. Like I said, I have never experienced anything like this before and it got me both....stumped and....MAD! LOL

 

"Fisheye" is a common adhesion problem that causes the new finish to bead up and separate like oil and water. Often it's caused by contaminates on the surface. Hard to say what is causing it. Silicone spray, oils, waxes (like Pledge or funiture polish are common ones) are some possibilities. I don't know if salt water could do something similar. It's a very difficult one to overcome, especially at this stage of the game. Did you do ANY preparation prior to spraying on this additional coat? Perhaps that could hold a clue.

It can usually be avoided by proper preparation before any additional coats of finish are attempted. Light sanding followed by cleaning with paint thinner and/or denatured alcohol, will usually prepare the surface, but depending on the sheer amount of contaminates on the surface, repeated efforts of sanding and cleaning may be needed.

 

It could even be contaminates in the spray equipment, depending on what was sprayed through the hose last. Thought I better mention that possibility too.

 

Hi XSleeper,

Your word "adhesion" does seem to fit the scenario that I'm faced with here. I started out by sanding the wood, then wiping it down with a microfiber cloth. I've been on many sites looking for a solution to the problem, one site will say to use a "tack cloth", another will say to stay away from a tack cloth and use microfiber cloth. They claim the tack cloth can leave behind traces of wax.

The microfiber cloth that I used to do the wiping was brand new, so there "shouldn't" have been any kind of wax or oil on it. Unless they're treated with something when they are made, which I have no clue to that. I have sanded with a random orbital sander using a 220 grit pad between each coat. In fact, as I said earlier, I've even scraped and sanded back down to bare wood and started over, and every #$%^ time.......I get the same dang thing!!!!! First, I thought that my gun wasn't atomizing the poly enough. But yesterday, I took a piece of scrap plywood, gave it a shot of poly and the gun seemed to be working fine. It was a thin coat and it soaked right in to the wood, so there were no "fisheye's".

On one of the previous shootings, I did wipe down with mineral spirits before shooting the poly......got the same effect and even though it felt dry to the touch sometime later, I could take my finger nail and scrape right through the finish to the wood. This deal with this poly has had me frustrated BEYOND belief!!!!! Especially since last year, the poly I shot on the floor came out beautiful! Same gun..same poly...same temps, and full sun. I'm tempted to sand again and try a brush, but.......I HATE USING A BRUSH.....especially when you have a piece of wood like I have with a lot of bolt holes in it, because no matter how careful you are, you end up with those big drops on the other side at each hole.

At any rate, I certainly appreciate your input on this matter. I'm at my wits end here, so I appreciate any and all feedback!

Thanks and have a great day!

Dennis

 

Hi again XSleeper!

On this HVLP sprayer, the only thing that comes through the hose is air. That's it. And I just cleaned the filter on the unit before shooting that last coat, even though it didn't really need cleaning at all. Just trying to eliminate ANY culprit or problem area. Since I've never had this problem before.....EVER!....I'd like your opinion on something here. If I sand this finish again, not back down to bare wood, but at least take off some of the high spots, wipe it down REALLY GOOD with mineral spirits, and then shoot again, do you think the poly would "fill" the moon craters (fisheyes) and give me a nice LEVEL finish???

Again, I appreciate the help your trying to give!

Dennis

 

Are you trying to apply the poly with just one coat [multiple passes] not letting it dry and sanding between coats? Generally it's a good idea to thin the 1st coat a little - helps it suck into the wood better. It's best to avoid applying the poly in direct sunlight.

 

According to some quick reading, spar polyurethanes are a lot softer than regular as they have to flex and move differently in an exterior environment. This allow for greater expansion and contractions. Prefered methods of application are brush and or wipe. To spray, thinning is recommended with multiple coat applications. I think your spraying straight from the can is the issue.

Here is an interesting article:
A Better Way to Apply Spar Urethane? | The Wood Whisperer

 

I don't know if microfiber has any pretreat on it either but it sure could. The one thing they definitely do, however, is they create a static electrical charge. I don't know what effect that might have if you tried to spray while that static electricity was there.

It might also be possible that when you sand with your orbital, the spinning action of the sander is heating up the old finish which is softening the old finish in some way.

You say you wiped with paint thinner, so I would have to ask about the thinner itself. Recently we had someone complaining about a bad oil paint finish and they were using a low VOC paint thinner which is not "real" paint thinner that should be used with any type of wood finish. Or it's possible that with the amount of sanding you did, that the soft spar urethane absorbed some of that paint thinner which if it didn't dry or if it left an oily residue, that is what's affecting the adhesion.

You say you used a new can, so I would have to ask if you stirred it (with a paint stick) to mix up the stuff at the bottom of the can? (not shaking it)

Oddly enough, I've also read of some people blaming the sandpaper itself... having trouble when they sand with one type and then not having the problem when they switch to another kind. Who knows. Fisheye is one of those problems that can leave even an experienced finisher scratching his head.

As much work as it is to strip and refinish, IMO I think it would be much easier to duplicate those pieces and start fresh with some nice new plywood.

 

Hi marksr,

Absolutely not! Even "I" know better than to do that! LOL I'm pushing 63 years old, and though I didn't spend my life as a carpenter / finisher, as I stated in my original post, I've just always had a knack for working with wood and I have never had this problem before. Also as previously stated, last Spring, I did the exact same thing under the exact same conditions, and everything went perfect! In fact, it was the first time that I had ever used an HVLP Sprayer, and I was AMAZED at the finish.......straight out of the can, no thinning, and that first coat soaked right in, no problem what so ever. That's why I'm so stumped at what's going on now. As far as spraying in direct sunlight, I really don't have much choice regarding that situation. I try to spray when the temps reach a proper level and the humidity is below 50%, and sometimes I even have to wait a little bit for the wind to take a break between gusts.

I know you guys are trying to help me get to the bottom of this and therefore you have to ask some questions and that's fine guys, ask away, I don't mind and I really appreciate everyone's feedback here. So, thanks very much to all of you!

 

Hi czizzi,

According to the instructions that came with this HVLP Sprayer, for oil based poly's, no thinning is necessary, and last year, I shot an entire sheet of the same kind of plywood (Arauco) with this sprayer, exact same brand of poly, no thinning, 3 coats with sanding between coats, and every coat turned out beautiful. You are right about the "qualities" of Spar Polyurethane, that's why I'm using it, the wood is being put in my boat. Right now, I feel like I've been beating my head against a dang brick wall and I don't know what else to do except......sand...AGAIN....and start laying down a coat that is so thin that it will be barely visible, and see what happens, and that's after a wiping down with mineral spirits.

Note: BTW czizzi, I actually did thin one batch of this poly before shooting it.....same dang results!

Brushing and wiping are alternative methods of applying poly, however, when you have a piece of wood with a lot of bolt / screw holes in it like the wood that I'm trying to shoot does, you ARE going to get those big sticky gobs on the underneath side of the wood at every last one of those holes, no matter how careful you are. At least....that has always been my experience, and I'm a fussy son of gun! LOL

Thanks for you input bud! I appreciate it!

 

Just to be clear, are you scraping because the spary poly didn't bond to the wood or because of the fish eyes?

Fish eyes are always caused by contamination, usually on the substrate. Normally a good sanding and another coat will fix the fish eye problem.

 

Hi XSleeper!

Well, everyone is putting out their ideas and I am absorbing and thinking about each and every one of them, and I'm going to do the same with yours too! I dug out two old, clean, t-shirts that I'm going to use for wiping down the wood with some paint thinner....it's not low VOC. But I must admit that I'm sitting here thinking about those "anti-static" sheets that I add to the dryer (BOUNCE brand) and those things feel waxy when you grab them out of the box, but then again, you'd think the paint thinner would dissolve any minute particles of that on the t-shirts. I'm going to try re-sanding and using one t-shirt to wipe with paint thinner and the other t-shirt to do the final wiping and see what happens. Now here's a bit of info for ya! I've ALREADY cut all new pieces and started over!!! Not because of a bad finish, but because of "bad fit". Like I said, I'm really fussy! So.....starting all over again is TOTALLY out of the question!!!!! I...REFUSE!!! LOL There HAS to be a logical reason for what's happening here and I'm determined to find out what it is, so I can avoid this ever happening again!

To be honest about the whole thing, I "think" it's a combination of things. PJmax said it looked like I put it on too thick. That could explain part of the "curing" problem, but not the fisheyes. The micro fiber cloths "could" possibly be the cause of the fisheyes. The fisheyes are causing the poly to "gather" making it even thicker than what I actually sprayed on. The fisheyes almost HAVE to be being caused by some sort of wax / oil / contaminate. So....I'm going to RE-SAND, and this time, I'm so desperate that I AM going to try my Tack Cloth (carefully!) then, shoot a really thin coat of poly and see what happens.

In the mean time, I'll keep checking this forum to see if you guys come up with something that I or the others haven't thought about that might be the culprit. Keep your eyes looking up in the sky guys and if you see some serious smoke coming up from the Pennsylvania area, you'll know that what I'm going to do this time...didn't work either and "I".........TOTALLY LOST IT!!!!! LMAO!!!!

 

Only other idea I might have is to use Naphtha (a higher quality thinner) instead of paint thinner when you wipe your sanded finish. I suspect some paint thinners of leaving greasy residue that can cause an adhesion problem. Any solvent you use to wipe has to flash off and evaporate before you spray.

 

Hi marksr!

I had to scrape the finish back off because it wouldn't cure! Dry to the touch, but still very soft underneath, and that was after two days of drying. And I have been keeping the wood in the house to protect it from drawing damp, and it's warmer in the house than it would be in the garage at night, so that should have aided in the curing process. I'll attach a pic or two here of what I was dealing with. This was the first coat which came out of last years left over can, and I thought "maybe" it had went bad, so I bought a couple of new cans. Same results! LOL

 

Having painted all my life I've used a lot of rags and T shirt material makes for the best rags!
Generally not curing is because of damp or cold drying conditions or the coating applied too thick, occasionally from a defect with the coating.

Will the smoke be coming from your boat or out of your ears

 

You are correct about the dryer sheets. They do leave a "coating" on the cloth fibers. Thats one reason microfiber cloths should always be washed separately from clothing with no type of fabric softener.

My rags get collected til I have enough for a small load. I do wash the microfibers with other rags, but none that have any oil or grease.

 

Hi marksr & Gunguy,

I think you're probably correct about the finish being applied "too thick". When I was scraping the finish off the first two times I was thinking the same thing. So the last time, I tried to spray a thinner coat on, but still got those #$%^&* fisheyes, which makes the poly gather into thicker pools.

Gunguy45.....you just confirmed something that I suspected but didn't know about for sure and I will dang sure heed your advice in regards to rags! Great idea and I appreciate the info!!!

Now, as far as the smoke is concerned....well, it will depend on the size of the EXPLOSION!!! There might be some smoke coming off of me too! LOL Guys, I am TOTALLY ASHAMED to admit this but......I was so freakin' MAD yesterday after I got done shooting that last coat that I actually entertained the thought of going to the garage and grabbing the ole sledge hammer, busting up all the wood and then caving in the side of the boat with it too! Thankfully, I got myself calmed down before I did anything stupid. I've always said and firmly believe that ANYONE, man or woman, can be pushed.....too far, and I guess yesterday was my day.

They say that practice makes perfect and I don't mind having to re-do something.....ONCE....but once it gets to the point of ridiculous...well...sometimes.....I scare even myself!!!!!! LOL

Thanks again everyone for all you feed back and help!!!

 

No need to be ashamed! we've all made plenty of mistakes, were do you think our wisdom comes from

Sometimes it helps to walk away from a project for awhile and go back to attack it another day.

 

Renegade,
I know the feeling. Sometimes you just need to step back for a bit and let it sit. Every time I'm doing some job and my wife hears me give a big curse...she comes and tell me to take a break.

The fact that your tests on other wood seems to indicate that your wood is just bad...for whatever reason. Have you bought new material and tried it?

I have to tell you this. My Dad bought a rear engine riding mower once (even though we had a large bumpy lawn on farm land) after his old Snapper tiller steer finally died. Well, not suited to our use and constantly burned deck drive belts. One day when it happened twice in about an hour, he said drive it over in front of the barn. He came out with a sledge, pick, and can of gas.
Beat it to he11 then burned it. Never saw such a satisfied look on his face as he watched. Then he looked at me and said..."well, that was probably stupid...".

Went the next day and bought a Cub Cadet (when they were quality built by IH, this was in '74) lawn tractor. That baby was still running fine 25 yrs later.

I'd try new wood (if you haven't already) after you test a few more pieces.

 

Might I suggest looking for some fisheye killer, it is used by auto painters on a regular basis so you may find some that will work with the finish you are using. Worth a try.

 

I've used 'fish eye medicine' with automotive paints but I don't know if it's compatible with oil base coatings. I'll look later to see if I have some and what it says on the label.

 

Hi marksr,

It's not my "mistakes" that I'm ashamed of! Making mistakes is all part of the learning experience in life! It's my......temper that I'm ashamed of. I went completely BALLISTIC and the sad part is.....those dang fisheyes were still there after I was done!!! LOL Conclusion: Blowing up didn't solve the problem, maybe made it worse! Total waste of time! LOL

 

Hi Gunguy45,

This "was" new wood. I'm taking the advice from you guys though. I'm taking a break! Didn't do a lick to it yesterday, haven't done anything to it today so far, and now I won't be able to because we are about to get dumped on by rain....big time!

You did get a pretty good chuckle out of me when I read the part about the old Snaper Mower with the tiller steering. My grandfather had one of those way back when I was just a young pup. Had the motor mounted in the rear, behind the seat. Reminded me of flying an old airplane in a way. LOL Dang thing was pretty neat in it's day! Your dad reminds me an awful lot of.......me! LMAO I have been know to literally DESTROY a few things in my time out of anger, then after I got cooled down, had to look for someone big enough to kick my a_ _ for being so stupid!!!!

As far as trying new wood again.....I just can't. I'm disabled and I'm in constant pain the whole time I'm trying to do ANYTHING to this boat and.....well.....I've just had it. I'm going to find a way to straighten out this mess, get it finished, and then finally be able to go enjoy some fishing. That....I can do without being in pain. UNLESS.......I stay out there for 12 plus hours like I did one day last year. I literally had to crawl out of the boat and then I had a hard time just walking to the car! LOL But dang it was fun.........

 

I'm with you on that one marksr! I don't know this to be a "fact" but......I seriously doubt that fish eye remover would work with spar polyurethane. I could be wrong though. Wouldn't be the first time that I was wrong!

 

I would like to thank all of you guys for your ideas, suggestions, input, feedback and help! You've all given me plenty to think about and try, and believe me....I was desperate! As a note here while I'm thinking about it, if anyone else needs help in a finishing project and you don't see any feedback from me, it's because I am not a professional finisher in no way shape nor form. In fact....this project that I'm in the middle of right now makes me wonder if I wasn't just "lucky" in the past! LOL

Have a great day guys!!!!! Good luck with your projects!

 

I forgot to look at the fish eye medicine this morning but was reminded when I looked at this thread

Brand name - That didn't tell me much it's sounds like it might work with poly but I guess you wouldn't know until you tried.

Looking at the pics and the fact that the poly isn't curing correctly, I can't help but believe it's more of an issue of the spar poly being applied too thick and/or additional coats to close together. It's best to apply separate coats letting it dry [and sanding] between coats.

 

I pretty much agree marksr! Yesterday, I got at and sanded everything back down to pretty much bare wood again. Rain today, so nothing done today. However, I agree that I was putting it on too thick. I also "think" that just maybe.....I was holding the gun to close to the wood. This time, I will have an almost perfectly smooth surface to work with....again....and I even sanded my "test" piece of plywood, and I'm not shooting ANYTHING unless things turn out well on the test wood. BTW: I "always" sand between coats, BUT!.....I wasn't sanding back down to a nice smooth finish before. I was just sanding some of the high points off, so I suspect that when I shot the next coat on, it only made things look even worse. Anyway....I'll let ya know how things turn out this time IF the dang weather ever lets me get back to work! LOL