PL bleed through finish

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Jason Stromberg
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PL bleed through finish

#1 Post by Jason Stromberg »

In the past i have had issues with PL bleeding through all types of finishes with the exception of hardwood veneer.

Tried a dozen or more types of primer and always the same results, worse on flat finishes but still noticeable no matter how many coats are applied.

Any tips on how to combat this issue ?

Bruce Weldy
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Re: PL bleed through finish

#2 Post by Bruce Weldy »

Jason Stromberg wrote:In the past i have had issues with PL bleeding through all types of finishes with the exception of hardwood veneer.

Tried a dozen or more types of primer and always the same results, worse on flat finishes but still noticeable no matter how many coats are applied.

Any tips on how to combat this issue ?
You mentioned primer, so are you talking about paint? Or stains?

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Jason Stromberg
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Re: PL bleed through finish

#3 Post by Jason Stromberg »

Bleeds through everything i have tried to finish cabinets with.

Primer, paint, duratex.

Bruce Weldy
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Re: PL bleed through finish

#4 Post by Bruce Weldy »

Jason Stromberg wrote:Bleeds through everything i have tried to finish cabinets with.

Primer, paint, duratex.

I've got 11 cabs built with PL and don't any kind of bleed through on a single one. Are you sure it's bleeding through, or is the seam just not sanded truly flat? I hit every joint with a random orbital sander and the PL sits right in line with the wood. After a flat black paint as primer and a couple of coats of duratex - it looks like one piece.

Do you have some pics?

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Bill Fitzmaurice
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Re: PL bleed through finish

#5 Post by Bill Fitzmaurice »

Bruce Weldy wrote: I've got 11 cabs built with PL and don't any kind of bleed through on a single one.
+1. For that matter I use PL to fill screw holes etc., it never shows through DuraTex.

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Jason Stromberg
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Re: PL bleed through finish

#6 Post by Jason Stromberg »

Bruce Weldy wrote:
Jason Stromberg wrote:Bleeds through everything i have tried to finish cabinets with.

Primer, paint, duratex.

I've got 11 cabs built with PL and don't any kind of bleed through on a single one. Are you sure it's bleeding through, or is the seam just not sanded truly flat? I hit every joint with a random orbital sander and the PL sits right in line with the wood. After a flat black paint as primer and a couple of coats of duratex - it looks like one piece.

Do you have some pics?
No pictures but it is just a bit shinier than the rest of the finish.

Spray and roll on primer, same results.

Oil, latex paint = same results.

5 coats = same results

Bill Fitzmaurice wrote:
Bruce Weldy wrote: I've got 11 cabs built with PL and don't any kind of bleed through on a single one.
+1. For that matter I use PL to fill screw holes etc., it never shows through DuraTex.
Used PL on many occasions to fill up holes myself, sometimes i miss something and don't want to mix up more bondo at the end of a day.

Works the same, fills the hole.

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Jason Stromberg
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Re: PL bleed through finish

#7 Post by Jason Stromberg »

Looked through all my pictures, could not find anything.

My camera skills are poor but next time i will try to snap a good photo of what i am talking about.

CoronaOperator
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Re: PL bleed through finish

#8 Post by CoronaOperator »

I think the flash you are experiencing is from 2 things. First, the PL is probably a little smoother than the surrounding wood and catching the light different. The second is that when your paint dries it probably stays wetter longer over the PL than over the wood causing the sheen to be slightly different from the different drying times. Latex and oil based primers won't solve either problem.

I always skim over any PL joints (except maybe inside corners) with autobody filler, then 180-220 grit on a random orbital sander to smooth them over and the whole box as well. For inside joints and places the random orbital sander can't reach, 180 grit on a flexible pad like the yellow ones Lealand sells are great. Most paint departments sell them. I cut off the top of the handle so it can reach into tight spots.

After that you are ready for primer to seal the wood and the PL. I use either a "2k high build urethane automotive primer" or an automotive "sandable laquer primer". The laquer requires more coats than the urethane. Both require a sprayer and a respirator although you can get the laquer in a rattle can. The rattle can laquer however is horrible as it is so thin it will run everywhere but it does sand nice and you can sand the runs out. With the urethane your neighbours (plural) will hate you from the smell, with the laquer, just your next door neighbours will hate you however with both primers, all the insects except for wasps in your city will die from the fumes. The wasps love the smell of those primers so they will come for a visit.

If that sounds too bad, then a shellac based primer like "kilz" will seal the PL and the wood to prevent any flash although with the kilz it won't build up and fill the wood grain like the automotive stuff will. It also comes in rattle cans for smaller projects.

After that I sand with the random orbital with 220, then reapply primer where you sanded through, a rattle can works good for touch ups, big sprayer if you need to do a larger area. Then apply a "guide coat". Then block sand by hand with 400 grit until all the guide coat is gone. The guide coat is the secret to an automotive like finish. For the 400 grit sanding I buy a roll of 3" adhesive backed paper on a long roll and a flexible rubber sanding block. Automotive paint supply houses stock these (and the guide coat) by the box. An old flat black rattle can can also be used for guide coat if you just do a very thin coat from far back.

After this, you can apply any paint you want as you have a surface as good as any autobody shop can do. It is a lot of work but the results will be stunning:

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Bill Fitzmaurice
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Re: PL bleed through finish

#9 Post by Bill Fitzmaurice »

CoronaOperator wrote:the PL is probably a little smoother than the surrounding wood and catching the light different.
For sure, if you don't sand it where you can or trim it with a chisel in tight corners where you can't sand it. Not only would it be smoother visually but without exposing pores it wouldn't hold a finish well.

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Jason Stromberg
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Re: PL bleed through finish

#10 Post by Jason Stromberg »

I use the random orbiter for the initial and maybe second sanding but block sand everything else to keep smooth flat surfaces.

After multiple coats of primer and block sanding after every coat there is no variations in the surface, its all flat and smooth before final coat(s) of finish.

Wish i had a spray booth but just no room for one.

CoronaOperator
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Re: PL bleed through finish

#11 Post by CoronaOperator »

Then try the shellac based primer to seal the PL and the wood. I bet its the difference in drying times that's causing the flash. You can use it at any time. First coat, middle coat, etc.
Built:
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2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
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Jason Stromberg
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Re: PL bleed through finish

#12 Post by Jason Stromberg »

CoronaOperator wrote:Then try the shellac based primer to seal the PL and the wood. I bet its the difference in drying times that's causing the flash. You can use it at any time. First coat, middle coat, etc.
That makes sense, i have noticed dry times are different between surfaces probably based on how porous it is.

Will give it a try on my next project and see if it makes any difference.

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Re: PL bleed through finish

#13 Post by LelandCrooks »

Rustolem 2x primer will fix it. Make sure it's the 2x. For anything I have to fill that's of any consequence I use elmers wood filler. Bondo shows up shiny, unless you get a really thick film, too thick I think.
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Jason Stromberg
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Re: PL bleed through finish

#14 Post by Jason Stromberg »

LelandCrooks wrote:Rustolem 2x primer will fix it. Make sure it's the 2x. For anything I have to fill that's of any consequence I use elmers wood filler. Bondo shows up shiny, unless you get a really thick film, too thick I think.
Bondo is a much better product than Elmers wood filler.

The Rustoleum product you mention is one of the many primers i have used, good primer but did not take care of the issue at hand.

Will try the shellac type next time, worth a try anyways.

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Charles Jenkinson
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Re: PL bleed through finish

#15 Post by Charles Jenkinson »

FWIW I've had the same problem - both PL and the stopper car body filler showing through the Tuff cab (UK equivalent of Duratex ). By about the third coat the sheen effect is reduced - I dont look close enough now to see if it still is a problem.
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