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Discussion Starter · #1 ·
Folks, I just finished my first DIY screen using artist canvas and CRT high gain Screen Goo. I'll take you through my trial and tribulations and then I'll take you through the steps if I were to do it all over again. Hopefully, this will help other first time DIY'ers. Learn from my mistakes and successes

My trials and tribulations:


I settled on a 96" * 54" screen size using a Barco Graphics 808s. I bought 12 ft * 64" of primed (gesso) artist canvas, canvas pliers and a custom 96 * 54 frame from an art store. When I got the frame I found that I couldn't get it down to my basement because of the landing. Sold the frame with the help of AVS classifieds. I bought the wood to build a new frame. With the help of a friend, we cut the wood, "dado'ed" the wood, mitered the edges etc. I assembled the frame in my basement. In the meantime I had the primed canvas rolled up lying on the floor for about a month. I had to paint the canvas first. Then bring it to the basement and stretch it on the frame in the basement because the assembled frame won't make the turn on the stairs. Here is how I painted the canvas.


There is an extruding plywood shelf in my garage about 10' long. With the help of a roommate, we used duct tape to tape the canvas along the edge of this shelf. I then used a piece of 8' long 1*3 of select pine and clamped this down on top of the canvas and duct tape on one end. I used another 1*3 section of wood and clamped that down on the other end. Jugs of Anti freeze where used to "clamp down" the centres. Now I have about 10' of canvas hanging from this shelf. I then clamped two pieces of wood with the canvas in the centre along the bottom of the hanging canvas to add weight. Because the canvas was in a tight roll for about a month - it has both vertical ridges from the roll and wrinkles about 1/4 and 3/4 of the way down from these lines. I used a steam iron to blast steam (on the unprimed side) on these spots and used the iron to iron out the hanging canvas from behind (the unprimed side). In some spots I held a piece of plywood on the primed side while I ironed on the unprimed side. The next day - the canvas was pretty much wrinkle free to the eye. I had some vertical ridges but I didn't worry about them as I could stretch these out once done.


I used a Campbell Hausfeld tankless High Pressure Low Volume air compressor (the cheapest air compressor they made / make) and a Campbell Hausfeld DH4200 all purpose spray gun. I put about 2/3 of the 1 litre of the CRT high gain primer in a tofu container. Added about 10-15% Reverse Osmosis water (pure water) and used a drill and paint mixer attachment to mix the water and primer for about 10 minutes. Put the primer in the spray gun canister and spayed some test spots on some scrap wood. I ended up using 30 psi and adjusted the spray gun for the amount of paint that was to come out. The spray gun is rated at a max of 50 psi. As per the instructions of the spray gun I kept the gun about 9" from the canvas and moved from one side sliding to the other along the 10' of canvas. I repeated this at different heights (from top to bottom) until the whole canvas was covered in primer. I then did the same thing but this time from top to bottom so that the spray pattern's would cross at 90 degrees. I noticed that some of my paint started to run (ie too much paint) at the bottom. This is probably because I didn't move as fast when moving the sprayer across the bottom of the screen as I was squating where as the other levels I was standing. Also, the canvas was already primed with white gesso so it was difficult to see if the primer was actually being sprayed on. This is why KBK's instructions advises the use of ton's of high power lighting which I didn't use. I thought my spotlighting in my garage was adequate. I was wrong. I did a No No by trying to fix the running / dripping by first using the air from the spray gun / compressor to blow the thick dripping parts more evenly and then decided to use my fingers - DON"T DO THIS. I messed it up a bit but on a second coat of primer - it didn' look so messed up. Luckily this was at the bottom and would be ultimately out of the viewing area when stretched. Both coats of primer seemed to dry fast. To be safe I waited about 6 hours (it was about 22 celcius outside) I then moved to spraying the CRT High Gain Screen Goo.


The Screen Goo Topcoat looked exactly like the primer in consistency. In one post, KBK recommended spraying the Goo on "dry". So I used less Reverse Osmosis water when mixing the Goo topcoat than with the primer. Again I used the drill and paint mixer. I had two drills on hand - one drill only has low RPMs - adequate but it will take you forever to properly mix. Use a High RPM drill. For the topcoat Screen Goo, I cranked the PSI to about 33 and adjusted the spray gun's trigger to allow more "paint" be sprayed from the gun so I could get a heavier "stiple" type coat as per another posts. I held the spray gun further back this time at around 12-18" back to create more of diffuse mist. I could tell it was going on "nice". I used the same motion that I used to apply the primer. I was worried that the Topcoat of the Screen Goo would "drip" especially since I used more base (from the 1 litre jar) of top coat than primer. There was no dripping / running what so ever.


A day later (today), the topcoat seemed dry (still a tad of tackiness) so my roommate and myself removed the clamps and the hanging canvas and carefully brought in from the garage to the basement where we stretched the canvas. We stretched the canvas in the conventional centre to outside method that is detailed on many web sites. I used a staple gun to hold the canvas in place. I thought I would still have wrinkles in the canvas, after we stretched it but to my amazement, us rookies had stretched the canvas as tight as a drum and it exceed my expections. Mounted the screen .........

The results:


The day before (yesterday) we were at Barry's, a friends house catching the Tyson Lewis fight and the hockey game. Barry has a Sony 1251 CRT on a 10' * 7.5' pull down screen. Looked pretty good. Today at my place with the new screen, I put on Moulin Rouge and my roommate who is not into HT immediately said "the colors are just jumping out and the whites are really white" compared to Barry's screen. Keep in mind that my Barco 808s is brighter and better than Barry's 1251 and I am running it on a smaller screen plus I'm running a better source. FYI - my projector is slightly out of convergence because I converged it using white paper on the wall. The screen is now 1.5" further out from the wall. Just from some quick testing. I walked to different spots of the room way off axis from the screen to see if the picture was still viewable and the answer is yes. Not a bad seat in the house!

Update June 29, 2002 The screen gain is creeping up. I've been out of town for a while and have not had a chance to enjoy the HT. Went to show my uncle and his family today the HT and I noticed that in scenes where it is white or a panning type camera action you can now see the vertical ridges very faintly. I noticed this in Kiss of the Dragon in the scene where Jet Li just finishes kicking the butt of Bridget Fonda's pimp and the pimp's henchmen in his "uncles" store. The main bad guy's right hand man then takes a machine gun to the place and as a result there is a lot of smoke and white dust when he is walking through it to find Jet Li. This is when I noticed the vertical ridges. I also noticed these faint vertical ridges when watching the test laps on Super Speedway. The reason why I didn't see these vertical ridges previously was that IMO the screen gain was lower now with time the Goo's screen gain goes higher as it dries. I am guessing the vertical ridges will become more apparent in a few weeks. I'll be travelling on business for the next three weeks and I will provide an update then. It looks like I will have to mask off a room in my basement to respray this time with the canvas strecthed. My Recommended step # 4 is holding ever so true now. end of update


Recommended steps - learn from my mistakes and my successes


If I were to do this all over again I would only change very few things:


1. if possible spray on the stretched canvas on the frame (this was not an option for me)

2. if you are a rookie like me, spray many light coats Screen Goo primer to avoid dripping and running like I had. If in doubt adjust the trigger on the spray gun so that the spray is on the light side. It is better to err on the light side than the heavy. I can't tell you the importance of getting the primer to lay down perfectly first time around.

3. if spraying Screen Goo primer on gesso primed canvas - use super bright white focused lighting so you can see the areas where the paint is actually sticking on to avoid concentrating too much paint in one area

4. Buy your canvas the day of your spraying or find a way to store it properly. Because my canvas was in its tight roll for about a month. I had some ridges because the round roll had some flat spots since it was resting on the floor and not suspended in spool. Even now if you look at the screen at certain angles (180 degrees) in full light conditions you can see alternating ridges via the paint. I noticed these when stretching the canvas. Thankfully these are not visible when viewing the screen in full light conditions at regular viewing angles. Most importantly, when a projected image is on the screen they are abolutely invisible. The ever slight "ridges" caused a slightly higher concentration of paint at the peaks than in the valleys thus giving a stripe type effect.

5. If you plan to make your frame buy the premade stretchers (the wood frame structure that the canvas is mounted on). I was going to go this route but the art store I went to did not carry stretchers that were 8' long. When I was in Victoria, BC a few weeks ago there was an art store that had 8' stretchers so I know they exist. If you plan to make your frame from scratch, you will need a bunch of wood working tools and a high level of precison to get the frame done right. If you can buy the frame premade by professionals and you can get it to your HT - go that route and save your self a whole bunch of PITA factor. The premade frame that I initially ordered and sold was only $80.

6. use canvas pliers to stretch you canvas - your hands won't have enough power. If they do they won't after 5 minutes. It took two rookies about 2 hours to fully mount the canvas onto the frame.


Thanks


Thanks to the those who have posted similar experiences which led me to make a DIY screen. I was looking at the various brand name screens but for the cost I decided to go the DIY route and I think I have a fairly comparable product with some effort of course. As a thanks for those in the Toronto area. If you want, I have:


- cut out excess from my canvas (the edges) that has areas where there is just the primed gesso canvas and areas that have screen goo CRT high gain primer and topcoat on. I have about 20 linear feet of this stuff at about 4" wide. if you want samples - I got some - price free! Added 6/10/02 > Just note that these excess pieces were folded so the canvas pliers could grip it. There are some wrinkle lines and the occassional teeth marks from the canvas pliers. Still very usuable for samples. Heck they're free!
 

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EC,


Thanks for sharing all your knowledge with us.


I also tried the canvas route but found one minor problem - the canvas, even after 4 coats of gesso and paint, was not smooth. In very bright (white) panning screens, the "grain" (or weave) of the canvas was still visible in many places (but on non-white pictures, it was hard to see unless you were looking for it).


Is the goo thick enough that it has covered up the canvas and its weave pattern?
 

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Discussion Starter · #3 ·
Rich,


I did not notice the weave patterns what so ever on the finished canvas. Just yesterday to test the new screen, I put on Saving Private Ryan and in the last battle scene there were lots of bright white skies / background and panning. I did not notice any patterns from the canvas at all. I notice even the smallest wave on other peoples screens so I am somewhat on the picky side when viewing. My temporary screen before this DIY were two long and wide sheets of white paper taped to the wall and you could see the grain (inconsistency) in this paper in the white scenes unquestionably. The best I can describe the "weave" is like a bunch or really small squares caused by the threading going in opposite directions and this is looking at the canvas on the unprimed side.


I bought my canvas preprimed with gesso as I looked at the unprimed and thought it would probably take me a million gallons of paint to cover that effectively. The small squares I mention above add a consistent texture throughout kind of like matte photographic paper. I have looked at the Dalite screens in our presentation rooms at work and they also have a similar consistent texture.


As for the Goo being thick enough? IMO I found the Goo topcoat thinner than the primer even though I used less water to thin it! Is the Goo thick enough to cover the weave IMO No unless you buy three or four times the recommended quanity :) I'm sure KBK will be happy. IMHO I think the recommended amounts are more than sufficient as you may not necessarily want a perfectly surface flat finish.


I assume you want to get a very flat finish say like a white board. Yes this is probably achievable but you will need lots of primer / paint and multiple multiple thin coats. You probably wouldn't want this anyway. Let me elaborate, behind the Dalite screens at work are whiteboards. When the projectors (previously CRT now DLP and LCD) shine on the whiteboards - major hotspotting.


Send me a PM if your if you want some of the excess canvas that I cut from the edges and I'd be happy to mail you a sample. Your eyes maybe more sensitive than mine.
 

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Discussion Starter · #4 ·
I have just provided an update in the original post that you may find useful. I thought this would have bumped the thread but did not.
 

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Discussion Starter · #5 ·
Goo part II


To get rid of the ridges that I stated in my original post, I finally got around to respraying my screen. In addition, I built a 4" black velvet mask around the screen and put it on the existing screen. The mask does wonders. All the posts about building a mask and using black velvet were 100% correct. A few months back I bought some more CRT high gain primer and Goo from Ken as in another post he said he would no longer be producing this hard to make but 'best' Goo product. I didn't want to start and then find out I didn't have enough paint / Goo. Now it is the holidays I finally have time to get around to this.


Since, I couldn't move the screen to the garage, I cleared a spot out at the back of my laundry / furnace room and a hung plastic "drop cloth" so there would be no overspray. Kind of like a spray booth. There were two fluorescent lights near the screen but I also used two 500W halogen work lights. Make sure you have adequate ventilation and that you wear a mask or ventilator for your nose / mouth as the sprayer "atomizes" the paint and you will have suspended paint as a mist in the air for about 5 - 10 minutes after spraying. The suspended paint mist ends up like sanded drywall compound dust. You don't want to be breathing this stuff in even though it is not toxic.


What is a DIY project without mistakes? I won't go into too much detail here to save face .......


Mistake 1. since I had 1/2 of container (in addition to the unopened jar) of the primer left I decided to mix the water and primer in that container. When I poured the primer into my spray canister - some of the small chunks of dired flaked goo/primer got mixed in. The spray guy started spitting and not spraying when these chunks got lodged in the mechanism.


Fix: pour and then mix the water and Goo in a separate and clean container.


Mistake 2. All my measuring cups disappeared when my sister moved out. Lets just say I used too much RO water when mixing the Goo and needed a squeegee on the screen to fix this problem.


Fix: for the second time around - I erred on the side of using less water. You can always add more water but it is impossible to take it out once added and mixed. The primer was on the thick side vs. the runny / milky side - it still went on like a champ with the sprayer. IMHO the thick consistency went on better than the milky consistency as it was when I first sprayed 6 months ago.


I resprayed the primer and then Goo a day after the above mistakes. Here are some further tips that helped me get a near perfect finish on my screen.


1. I put water in my spray canister and adjusted the spray amount and airflow combination to get an approximation of the amount of spray size / area / amount and airflow. Once I felt I got the right mix (about 28 - 30 PSI) and very light amount of paint, I then emptied and dried the canister and spray gun. Once I put the primer or goo in the canister, I test sprayed outside of the screen to purge existing water in the spray gun.


2. I used 3M blue tape (I use it for converging my CRT) and put markers on both the right and left vertical sides of the screen every 3". Every 4 pieces of blue tape I used regular beige masking tape to mark this off (12"). Now when I sprayed from one side to the other I could do it fairly straight. Since all the markers were blue, I used the 12" beige marker as a reference to where I was. For example, I'm on the 2nd blue marker above the 2ft mark etc. I used 3" as I found this gave me a decent overlap from the "wet edges" of the previous pass from the sprayer. I avoided visible lines because of this overlap. I did not need to spray vertically. All 17 passes to cover the entire screen were horizontal. Not sure where I came up with this idea but it worked wonders for me.


2a - if in doubt hold the sprayer farther back rather than closer to the screen. You will avoid a thin thick band and instead get a more disperse wide band.


3. see my second tip from the original post. I did many (4 or 5 thin) layers of both the primer and Goo. It takes a more time but it makes amateurs like me look like pros when you look at the finished product. When I went this route, I estimated that I used only about 200 ml each of primer to cover a 96" * 54" screen.


3a check how much primer or goo you have left in your spray canister after each coat. Why? You don't want to get low on the paint and then have the sprayer start spitting (inconsistent air / paint mix) out the remains when you are part way through and wreck you "perfect finish". If you don't think you can put another thin coat on without spitting - don't do it.


4. Surprisingly I didn't like using the 1000W of halogen lighting while spraying. Because of my spray booth, when I used the high power lighting it created two shadows. One from my body and the second was from the wire grill protecting users the heat from the bulbs. The fluorescent lights were sufficient when spraying. Also the breaker on my power bar would trip every so often with the lighting and air compressor going. But once I finished one coat of spraying I did turn on the powerful lighting to look for missed spots. Luckily with my 3" markers - I didn't have missed spots.


4a - I found the best way to view the consistency of the coat was to use only the flourscent lighting and view the screen surface from a 45 to 170 angles. You can more easily see the spray patterns vs looking at the screen dead on as if you were viewing a movie.


Well I just finished spraying and let the last coat of Goo dry for 30 minutes. I couldn't wait so I mounted the screen again and put on some selected chapters from some of my reference movies.


Resutls Part II


1. the screen didn't seem as bright as previously. If I remember correctly the gain will begin to creep up the more the Goo dries.


2. The Goo didn't seem to have that same tacky feeling. When I first sprayed I used less but thicker coats. This time I used more but thinner coats.


3. The colours still seemed very brilliant. In LOTR - the greenery in the "shire 60 yrs later" near the beginning is very brilliant. The contrast between colours was great. For example, in Shrek when he and Donkey are walking in the sunflower patch, there is blue sky against the green leaves and yellow flower. The colours in this scene are very distinct and seem to pop up at you.


4. Blacks seemed to be blacker. I assume this is related to # 1


5. I did have a small horizontal band near the centre of the screen. This can only be seen if you look very very carefully at scenes where it was very bright with the same light colour and the camera pans upwards or downwards. This is why I put in tip 3a. The screen had near perfect consistency but I thought what the heck I would use all the Goo up. Please note that this band was still wet so I'm guessing and hoping it will disappear when the Goo dries.


6. I still have a very 3D effect with the screen. I noticed this through out in all scenes.


I'll post again in a week when the Goo has some dried more as I put the movies on about 30 minutes of the last coat.


The high gain CRT Goo seems to be a good product. Too bad it isn't available anymore.
 

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Discussion Starter · #7 ·
I can only include finished pics - and they will be pretty boring to the eye of a digital camera. Bascially, here is what I did with the help of a friend as he has the table saw. These are basic steps so I may be missing parts.


1. measure the outside of the unmaksed screen. In my case it was 96" * 54"

2. you will need some 1/2" plywood, black velvet, glue, nails, screws, patience.

3. cut the plywood lengthwise so that you have 4" (or your desired thickness of the mask). The thicker the mask the better the effect

4. cut thinner strips that will be your resting frame of the mask. Mines about 1.5 - 2 "

5. Since my screen is 8 ft wide - the mask will have to be longer. Each of the 4 sides will be longer than the screen itself. So pieces of plywood were joined together to make it longer for the top and bottom - say 102". 6. Cut the ends of the 4 pieces at 45 degrees

7. attach the thin strip 90 degrees to the shorter side (inside) of the side pieces that will make up the mask. I used nails and glue. I put this thin strip about .5 - 1" in from the bottom of the shorter side of the side mask. The .5 - 1" represents the "overhang" on the screen so if .5" is used, my viewable screen area is now 95" * 53". The thin strip has to be also cut at 45 degrees at the end.

8. At each corner of each of the mask side pieces - another thin strip was put on with mitre joints to the 4 pieces can fit together.

9. You will now have 4 pieces that will fit like a puzzle. And when assembled look like a big picture frame.

10. hang the mask to make sure it fits - otherwise - return to step 1 :D

11. disassemble the 4 peices

12. get some black velvet. Make sure you when you buy the material you have enough length for the long side. In my case I bought 10ft. Cut the material in strips so that the edges can be folded over at the back. In my case this was 7.5"

13. Staple the velvet to the back of the mask sides so on the front all you see is black velvet. Do this for all four pieces

14. reassemble the four pieces

15. mount the mask and voila $30 later your have picture that looks like a million.



Also.....


I hijacked this from JMHays in another thread ..


jumpman,

There are a number of great ideas for masking systems, look here:

http://community.webshots.com/album/20548922LrrFAMIZzI


read this thread:
http://www.avsforum.com/avs-vb/showt...hreadid=173867


and then for the absolute best link for a masking system, look at Kathie's here:
http://www.kathiejohnson.com/masking.html
 

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Discussion Starter · #8 ·
Its been three weeks and the Goo is dried. Here is what I noticed....


The screen doesn't seem as bright (same projector settings) as my first Goo'd DIY screen. I wonder if KBK sent me the low gain screen Goo in the high gain container by accident? I used multiple thin layers of base and top coat so I thought this would give me higher gain.


The edges of the screen screen seem to be slightly darker especially in darks scenes. I did put a velvet mask around the screen where as in Goo Part one, I did not have a mask. This may have something to do with it.


The horizontal band from the undried wet paint is gone.


I got rid of the ridges from Goo Part I so I'm happy about that but I don't like the loss of gain especially around the edges but I'm willing to live with the trade off.
 
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