LumberJocks

Earlex issues

  • Advertise with us

« back to Finishing forum

Forum topic by moke posted 08-18-2015 06:06 PM 1053 views 0 times favorited 25 replies Add to Favorites Watch
View moke's profile

moke

862 posts in 2243 days


08-18-2015 06:06 PM

I was spraying some oak this weekend with an Earlex 5500. It is fairly new to me. I was spraying water-based poly. It was warm, aqlmost 90 outside, however my garage is air-conditioned, well kind of…..long story, but the air conditioners keep it around 80- 82. It was humid too, but again, not as bad inside. I filtered the mixture of 90% poly and 10% water, and sprayed it 4 times…the first two times I got a good even coat so I sanded with 400 and put the last coat on, then after it was dried I noticed some air bubbles in the finish. I then resanded, cleaned the surface thoroughly…even with a tack cloth, cleaned the gun, refiltered the finish and got the same issue, only worse. There are not a lot of air bubbles, but enough to ruin the finish in my opinion.

Has anybody got an idea of what I did wrong? should I have thinned with flotrol instead of water, was humidity a factor…..I turned off all the fans and AC units while I was spraying and it was drying….

Thanks in advance for ANY suggestion.
Mike


25 replies so far

View mahdee's profile

mahdee

3555 posts in 1235 days


#1 posted 08-18-2015 06:16 PM

Water base finishes are usually more difficult to sand even especially if you don’t allow for 3-10 days drying time before the final coat. After sanding the material evenly, the last coat should be heavy enough to create a thick coat without causing runs. This will prevent the finish from looking like spackles from the spray.

-- earthartandfoods.com

View moke's profile

moke

862 posts in 2243 days


#2 posted 08-18-2015 06:38 PM

After I sanded it, I thought it looked really good…...I did sand it by hand, should I have used a 1/4 sheet sander or even a ROS? It was a thick coat…they were oak boards laying down….I am wrapping a pole in my basement. Is it possible for it to be too thick? I thought since there was no chance of running….why not?

So just to be clear, I should wait three days before sanding?
Mike

View mahdee's profile

mahdee

3555 posts in 1235 days


#3 posted 08-18-2015 06:48 PM

Yes, Mike. I think maybe the first coat didn’t dry all the way before you sprayed the second and this causes the finish to dry even slower. The best bet is to wet sand it after it dries. If you sand it dry and don’t get a fine white powder, then it is not ready for sanding. It should feel like you are sanding a nice dry board. Otherwise, it is not ready yet. I saw a video with Charles Neil and I think he waited a week to 10 days before he wet sanded a countertop. I’ll see if I can find the Youtube video for you.

-- earthartandfoods.com

View firefighterontheside's profile

firefighterontheside

13520 posts in 1324 days


#4 posted 08-18-2015 06:49 PM

What finish are you using. For waterborne I usually use minwax polycrylic. I don’t thin it at all and use the 1.5 tip in my 5500. I assume you did not shake the mixture. I don’t think sanding within three days is the issue. Are you using a 1.5 tip? It comes standard with a 2.0 tip and that is not best for finishing. Rather the 2.0 is better for painting.

-- Bill M. "People change, walnut doesn't" by Gene.

View mahdee's profile

mahdee

3555 posts in 1235 days


#5 posted 08-18-2015 06:51 PM

Here is one of many.

-- earthartandfoods.com

View mahdee's profile

mahdee

3555 posts in 1235 days


#6 posted 08-18-2015 06:55 PM

Here is part 1 of sanding poly.

-- earthartandfoods.com

View Drew's profile

Drew

304 posts in 2567 days


#7 posted 08-18-2015 07:07 PM

3 days? No way.
I spray 3-4 coats in a day every week, hundreds of tables, sanded between most coats with 320 or even 220.
You don’t need to wait 3 days.

To be able to help we really need to know what finish you were shooting, but I do have a few suggestions.

First, never use a tack rag. You should use a 50/50 mix of denatured alcohol and water.

You are probably not getting good atomization. It’s hard to push WB with a small turbine.

The way I like to lay down WB is a lite coat first, then a medium followed by a heavy coat. Last coat really needs to be on the heavy side (depending on what you shoot).
Avoid that last “extra” coat. This usually causes issues like this with WB.

-- TruCraftFurniture.com

View OggieOglethorpe's profile

OggieOglethorpe

1213 posts in 1577 days


#8 posted 08-18-2015 07:32 PM

Tack cloths are not compatible with most WB finishes. The alcohol mix ^^^ works fine, as do clean microfiber dusting cloths. What you are seeing may be small fisheyes, not bubbles. It’s perfectly normal to apply several coats in a single day with better quality products, like ML Cambell or General Finishes products.

Here’s an example of a good product info sheet: http://www.paintdocs.com/webmsds/webPDF.jsp?SITEID=MLC&doctype=PDS&prodno=035777776926&lang=2

See if you can get one for the product you’re using.

Also, many WB, as well as catalyzing solvent finishes have a maximum dry finish thickness before they go wonky. It’s common for beginners to apply too many or too thick coats. ML Campbell lists the wet and dry coat thicknesses in mils, I’ve used the same numbers with General Finishes products with excellent results. It’s not Plastidip… ;^)

I like to do a relatively wet coats, sanding the first (sealing coat) with 220 . My original WB training was by an ML Campbell rep. Doing a very light “tack” coat as you’d do with solvent lacquer never worked well for me.

View Fred Hargis's profile

Fred Hargis

3950 posts in 1960 days


#9 posted 08-18-2015 09:33 PM

I agree the waiting of 3 days isn’t needed. A couple of thoughts: if they are air bubbles, they may have been trapped buy the finish not letting itself flow out (dried too fast). If true, Floetrol would help with that. But if it’s fish eyes (go through your tack cloths in the fire, and write I will never buy tack cloths again 10000 times on the blackboard) you may have contaminated the surface somehow. Someone else mentioned it: if you sand and get white dust, your good to go. True enough, it may take a waterborne some number of days to fully cure, but it’s workable very quickly.

-- Our village hasn't lost it's idiot, he was elected to congress.

View moke's profile

moke

862 posts in 2243 days


#10 posted 08-19-2015 02:01 PM

You know I have used tack cloths for years and NEVER liked them. I never heard they can cause issues…I wondered though, if they put the same crap on the wood that they do on your hands, that would be bad. I was taught to use them by the man that mentored me, and I never really questioned it.

The material I used was Minwax waterbased Poly for the first three coats and Rustoleum water based Poly on the last one. When I sanded it did not create dust, but I didn’t really take much off. And I did shake the can….whoops…I just did it without even thinking.

From the sounds of it…it is wonder I got as good of a finish I did!!!

Thanks to everyone for the help,
Obviously I needed it…....
Mike

PS—I have several needles—-I used 1.5

View firefighterontheside's profile

firefighterontheside

13520 posts in 1324 days


#11 posted 08-19-2015 02:27 PM

Are they both the true water based poly or is one what min wax calls oil modified? I believe the latter may not be water thinnable. I’d have to check that though. From what I’ve seen the water based stuff says water clean up and the other stuff says soap and water clean up.

-- Bill M. "People change, walnut doesn't" by Gene.

View Earlextech's profile

Earlextech

1159 posts in 2157 days


#12 posted 08-19-2015 02:27 PM

I’m here if you need me. But I think everyone has covered it already.
Tack cloth – never with water based finishes, use a water dampened rag
Floetrol – not a thinner, water is the thinner
Stir gently, never shake a can of finish
Use the 1.5mm needle
Spray from about 6” from the project

-- Sam Hamory - The project is never finished until its "Finished"!

View moke's profile

moke

862 posts in 2243 days


#13 posted 08-19-2015 02:49 PM

I just bought waterbased Poly….I had no criteria….the Rustoleum, I had actually used to brush on many times.
Can anyone recommend a water-based finish that I can buy at a big box store….while I understand ther are probably better finishes around, I will probably still buy at Lowes, Home Depot, or Menards….they are right here.
Thanks
Mike

View mahdee's profile

mahdee

3555 posts in 1235 days


#14 posted 08-19-2015 02:59 PM

I think they have a few brand of water poly at HD including minwax. I’ve never used the minwax but my wife use it all the time.

-- earthartandfoods.com

View firefighterontheside's profile

firefighterontheside

13520 posts in 1324 days


#15 posted 08-19-2015 06:05 PM

I have heard that it’s is soft, but I really like minwax polycrylic. It is water based, dries fast and I can spray it with my 5500 without thinning. I’ve had great results with it. Many places only have it in quart cans, but it can be found in a gallon. I believe HD and Lowes both have it.

-- Bill M. "People change, walnut doesn't" by Gene.

showing 1 through 15 of 25 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com