BW and Dark Spots

1. In my experience, no, the surface should NOT look like really course sandpaper (like 36 grit). At it's roughest, I would guess maybe 120 grit. In normal, or even bright, room light there should be no apparent texture an arms length away from the screen; unless you're talking about a kind of granularity caused by the reflections off the aluminum flakes on the surface.

I can send you a small sample to compare your screen to if you would like. Just PM me an address.

2. Sorry to make you repeat yourself, but what kind of substrate are you using again? If it was primed, was the primer sprayed on? Was Kilz2 used? Sorry again - I should remember this data, but I don't. I'm gettin' old...

How much did your friend have to dilute the BW?

I just thought of something... you are using the HE558 5:1 mix right? When I sprayed my panels using HE558 mixes I found that the screen would tend to "smudge" if it was handled with bare hands even weeks after it "dried". Are the dark areas you refer to places when the screen could have been handled? This wasn't a problem when these mixes were rolled.

No, do NOT sand the screen! While I have never tried that, I think it would do more harm than good. My advice would be to apply another coat of BW. After it is dry, only handle it while wearing latex or nitrile gloves. The current theory is that oils from the skin somehow react with the asphalt in the HE558. My humblest apologies for not mentioning this before. I think the info is in the BW thread somewhere, but that is no excuse.

Harpmaker thank you for your help.
My material is BOC. ....It was primed 5 times with kilz2. Yes it was sprayed on.
Im not sure how much he diluted the BW...He has a body shop and he has a professional setup. He paints cars all the time.....So although Im not sure how much he diluted it, I'm sure he diluted it until it sprayed correctly through his gun.
Yep, Im using HE558 5:1........I really dont think those dark areas are smudges, they are almost in the middle of the screen. Although I was not there and cannot say for sure if he handled that area, I would not think so because of the area that it is in.....I'm gonna talk to him more about it but he did say after I asked him about those "dark spots" or areas that look like there were a different texture than the rest of the screen (more course) ........he said that it looked like that from the first coat of BW......so I'm not sure that adding another would help.......maybe that part of the screen had oils from hands or something before it was spray.....this I just dont know....it's really hard to say what the extent of the courseness is.... I'll get some 120 girt sandpaper and compare it to get an idea....Please try to be accurate with your comparison to that grit of sandpaper............and yes I will PM you and would really really appreciate a sample of what the texture should be........Remember...I'm using BOC........
I assume if it is more "course" than it should be that means that he didnt dilute it enough correct???? thanks again for all fo the help and I apologize for being a pain.......This project is turning out to be WAY more than I can handle.........I'm getting a little discouraged....Thanks again sincerely.....Riff

When I sprayed my panels it was around 60 degrees F and medium humidity and my coats usually dried to the touch in about 10 minutes, but this depends greatly on the equipment used and how thick the paint can be applied before running. The higher the humidity the longer it will take the coat to dry; higher temps would help, but the atmosphere must be able to take up the water from the paint.

I have never painted BOC, and the more I learn about BOC the more problems I see painting it. It is doable with most BOC's, but there is a HUGE difference in what is being called BOC!

I ordered two different type of BOC from JoAnn Fabric and they are two VERY different fabrics. One is totally opaque to light (I've posted photos and specto data on it elsewhere) and the other looks like a bedsheet! It's very translucent and looks almost like a gauze! I have no idea how it could be used to block light.

Riff,
Is your BOC coated on one side and uncoated on the other? Which side did you have painted? Again, sorry for my bad memory.

At this point, I'm wondering if the "dark spots" (caused by differences in screen texture) weren't in the fabric to start with, they would be hard to see on a white fabric unless a bright light was held at an oblique angle and texture differences looked for.

The other possibility is that the Kilz2 had to be thinned so much that the water reacted with the BOC in some areas differently than others. I'm saying this because the sprayer said that the first coat of BW had the spots, therefore it can't be smudging.

You're not being a pain Riff, not at all. I really hate it when someone has this much trouble getting a screen done.

As for the paint being rough, it can't really be called that unless comparing it to a glass-smooth surface. I did a test today (photo below) and you really can't use sandpaper grits to compare screen surfaces. I was wrong to compare BW HE558 to 120 grit, as you can see from the photo. To make long short, BW is not the cause of the texture on your screen; I sincerely think it's the BOC itself, or it's reaction to being painted with the primer.

In the macro photo below, the total width of the image is about 3/4 inch. The cream-colored material on the left is 60 grit sandpaper, the dark rust-colored material on the right is 120 grit sandpaper, the gray area is BW Winter Mist/HE558 5:1. Lighting was overhead fluorescents and a bright L.E.D. flashlight at a low angle from the top of the picture. Only the bottom area of the photo is in focus, but the grain-size of the sandpaper and BW can be seen. The aluminum flakes in the BW are very apparent, and in the area in focus, little black grains of the asphalt can be seen. This is a VERY close-up photo folks. :bigsmile:

Harpmaker said:

Riff,

Is there any way you could post some photos of the spots? That might help a lot.

If they are caused by differing thicknesses of BW then the guy that sprayed the screen is at fault. I wonder if they could be areas where the paint sagged a little?

I can't help but think that sanding a BW HE558 screen would be a recipe for disaster, but it sounds like you have little to lose. Even if the BW is dry, it won't be cured for months (in my experience). I'll sand a portion of a test panel and get back to you with the results.

Again, sorry for making you repost info I'm sure you've given before; but what size is your screen horizontally and vertically? Was it mounted on it's frame when it was sprayed?

Dark spots aside, how do you like the screen image?

Click to expand...

My screen is 4 foot 3 inches vertical. 7 foot 6and 1/2 inches horizontal.....104 inches diaginal.
The cloth is streched around the back of the frame (was done before sprayed)....so the image is "framed".....there is NO support on the back of the cloth....otherwise I would have just rolled it....I could have tried that myself......I'm working on some pictures now...I can take them...just no idea how to post them......
The best way that I can describe the spots is if you had a piece of glass and evenly spread sand all across it......except in some places the sand build up more than in the other places...(it's very course in these areas)....this is causing a darker looking spot than the rest of the screen....These areas are not visible all the time...from a front view normal lighting you cannot see it (projector off) but with the projector on with a light scene you can see it (I wouldnt care except for this)........also with the projector off with good lighting and a side view it is very visible........... I think that is the best way I can describe it....
Im gonna try the sanding...and im sure it's gonna mess it up royaly....at the least I'm sure the area sanded will be lighter than the rest....That's my last shot im afraid....I'm sure he would spray it again for me but I'll have to get more cloth....unstaple the zillion staples....restaple....bring it back to him....with no guarentees that it will come out right the second time.....this guy knows what he's doing when it comes to painting...like i said, he owns a body shop....but painting on cloth was very new to him too.....thanks again everyone....ill let u guys know how the sanding turns out...when i get the nerve to do it. :hide: ...Riff

I think if I paid someone to do the work I kinda would demand that they take the responsibility to do it right. I can see where being on a budget is a concern, but this has been sprayed before and if the surface is prepped right it will come out right.

I'm not trying to be a jerk here, just saying that since is has been successfully sprayed a couple of times that it can be done. You shouldn't have had to repay, they should have made it right.

If I paid someone to spray my car with Emron paint and they accepted the job but seeing it is a unique type of auto paint and perhaps they thought it was easy money but never sprayed it before I might be lenient with them and try to work through things, but in the end they took money and said they could do the job so I would hold them to that... or ask for my money back.

Again, like I said, I'm not trying to be a jerk here, just saying when you pay someone for a service and there is a problem with the work it's their responsibility to make it right one way or another.

In the end, if you are happy with BOC, then that's all that really matters, but I'd still at least ask for a refund.