Starting Out on the project

In contrast to the end result, here is what the Dover yard side of the divider looked like before.

So the starting point was material selection.  While this side of the divider might have worked to use 1/8" masonite, the other side would not.  The outside corner on the other side would have been a problem for how sharp a bend I needed.  And at the near end not visible in this photo (visible more from the finished photo and some to follow) there is a similar outside corner on this side of the divider.  So I was in search of a material that would be more flexible for the task.  I first considered DuraFlash but learned on these forums that it would require continuous contact to avoid potential for sagging.  A bit too flexible for this use.  I considered sheet styrene but I wanted something I could source locally, so I put that on the list for if I didn't find something local that I preferred to go with.  Old fashioned thick linoleum was my next consideration.  But the only floor coverings I could find were the newer vinyl that is way too bendy - not rigidity at all.  I was at Lowes for something else when I decided to see what else they might have.  That was when I found the .09" thickness FRP.  The flexibility seemed about right for my purpose, yet it seemed very sturdy and durable.  When I got home, I did some research, including my questions here on MRH.  Here are some of the things I learned:

• It is non-toxic and is commonly used in applications involving food storage and preparation areas.
• It is extremely resistant to scratching, denting, or breaking.
• Because of the fiberglass composite, it could be a mild irritant is inhaled or on the skin when cutting or sanding it.
• Multiple approaches were indicated for cutting it including saw, tin snips, or scoring and snapping it.  One MRH reader with some experience with the material indicated scoring and snapping was not very effective.

I bought my materials including protective materials like disposable latex gloves and disposable masks and started work.  I needed new tin snips anyway and found a great pair that has the handles offset from the blades to allow both handles to remain above the material.  I measured and put down a chalk line for the 20" backdrop material height and started cutting.  The tin snips worked fantastic!  Here is a photo below partway through one cut.

I was thrilled.  No mess and really quick to cut.  

Next it was time to test fit it in place.  The material is pretty light, so I was able to do this single-handedly.  Just carried it into the layout room and proceeded to first loosely position it and then ultimately test clamp it in place. At the end of the divider I used wood scraps as stops so the material could be stopped at the end of the divider.

Wherever I had an outside corner, I was able to use 1"x2" bracing to create locations for screws top and bottom to provide "just enough" curve.

Test fitting done, it was time for sanding.  I will pick up there in my next reply.

-Ed

Free Image program

If you work with Windows, there is a great free software for compression etc called FastStone Image Viewer.

Thank you for sharing your work with the backdrop.

Sanding, priming and affixing the FRP

One VERY important point that I forgot to mention above.  The FRP has a smooth side and a pebbled textured side.  Technically the textured side is the front, but of course for our usage the smooth side is what we want to be using as the front.  In these postings, if I refer to front or back, it will be the way OUR application needs it - so I consider the smooth side to be the front and the textured side to be the back for our purposes.

When I was test fitting the FRP, I had marked all the locations top and bottom where I would be using screws and washers in addition to the adhesive.  If the FRP were going to have continuous contact with the plywood, screws would not be needed.  But since I was also bending around corners, there would be stretches with no contact, so i felt screws would help ensure the curves started and ended exactly where I wanted.  Before sanding, I drilled holes for the screws.  The holes should be LARGER than the screws you will be using by about 1/8".  This is because FRP does expand and contract some with variations in temperature and humidity, so it requires any fasteners to have room for the FRP to move a little and the same at top and bottom of the FRP.

It is uncertain whether sanding and priming are a requirement with FRP, but a number of sites made mention of paint potentially pulling away over the long term if simply applied to the FRP as is.  Since this backdrop is meant to last for decades, I thought it best to take the extra time to sand and prime.  Thanks to an MRH reader suggestion (thank you Rick) I decided to wet sand.  This was simply a matter of a bucket of water that the sanding block was dipped into frequently so the sanding was done wet.  I am not sure what the best choice of sandpaper would be, but I chose 200 grit and my result worked well.  I simply sanded wet using a random circular pattern to avoid leaving any visible sanding pattern.  You can tell it is working because the water turns slightly milky looking as you sand.

Above are the materials before I sanded.  I also took the extra step of wiping down the panels with denatured alcohol before wet sanding and I did it again afterwards after I have wiped the panels dry.  I do not know if this is necessary, but another MRH reader suggested that the alcohol wipe down might be beneficial after sanding depending on what the composite resin in the panels contains.  It only took a minute extra.

Next it was time to prime.  Because this is a non-porous material, a bonding primer is advised.  I chose the Valspar bonding primer shown below.

Although the can says latex, it actually uses a bonding agent plus an acrylic binder.  I just rolled it on and left it to cure.

While it looks shiny above, once it had dried about 8 hours later it was a nice flat finish.  

Once dry, it was ready to mount.  Mounting requires FRP adhesive as well as a notched trowel.  The FRP adhesive calls for a trowel that leaves V shaped beads.  Size is 3/16"x1/4" notches.  The one step I forgot to photograph was the adhesive spread on the back (textured side) of the FRP.  You only have a short time from opening the FRP adhesive and spreading it to permanently positioning the FRP.  Although no pictures, if you have laid ceramic tile then you will be familiar with using a notched trowel to spread the adhesive.  If not there are many good YouTube videos on it.  This is the one stage where I needed a second person.  If I did not already have some trackwork in place, I may have been able to do this step alone, but I did not want to risk getting adhesive in the trackwork while lifting and positioning the FRP into place.  My procedure was simple:

• I trowelled out FRP adhesive onto the textured side of the FRP in the areas that would be in contact with the plywood,
• I then used the notched trowel to appropriately spread the FRP beads uniformly throughout those areas using an arcing pattern just as one would when putting down ceramic tile.
• I then CLOSED the cover on the FRP adhesive so the bucket of adhesive would not start to dry.
• Then my wife and I (thank you honey!) while wearing latex gloves picked up the FRP and carefully positioned it.  This is the KEY step:  Once the adhesive meets the plywood it doesn't want to move much.  We positioned it and then QUICKLY used our hands to ensure any minor positioning adjustments were done.  
• While my wife made sure the FRP was staying in the right place (which it did on its own due to the adhesive), I put in the screws with washers in the pre-drilled holes top and bottom.  

At that point we were done affixing the FRP and it could be left to dry over night.  

The next two photos show how the FRP on both sides curves around the inside and outside corners and how I positioned the screws and the 1"x2" bracing to help form and maintain the curves.

The screws near the inside corner may be surperfluous but I figured they might reduce the strain on the adhesive.

Final step was to paint the backdrop blue this morning after the adhesive had dried overnight.

As I indicated in the start of this blog thread, I am very pleased with how this worked.  The flexibility and durability are a great combination.  I am not sure if I will use this to cove the corners of the room or if I will use styrene for that.  But I will definitely use this for my fascia.  Besides the flexibility, it will make it very easy to cut the fascia upper edge contour for the scenic contours of the layout using the tin snips.  

I would be happy to answer any questions I can with regards to my use of the FRP.

-Ed

@KnuT If you work with

@KnuT

I will check that program out.  Although I ended up posting less than 20 pictures for the overall process, so I got it all posted today, ridding myself of that limitation will be great.

And your welcome regarding the sharing.  I originally was thinking it could become an article submission, but I just don't have the photography equipment or photography skills needed to meet the standards for photos in an MRH article.  So I chose to blog it instead in the hope someone in the future might find it helpful.

-Ed

Some finishing touches - clouds

I decided to try my hand at some clouds as a finishing touch.  If I decide i don't like them I can always do some repainting though I would want to do that before I move on to trees/mountains.

Any thoughts on how they came out or ways to do better? (I am not an artist, so I would be grateful if you can temper critiques with some supportive suggestions - thanks).  The top 1/4 or so probably won't even be visible once the valance is up and the bottom will have trees close up on the Dover yard side and further away trees/hills on the Madison NH side.

-Ed

FRP Backdrop and clouds

Looks like it is turning out well. I admire your considered approach in trying out a different material for backdrops...carefull research, intelligent planning and thorough preparation.

Recognizing that this might be an artifact of severe lighting in the photos, I am seeing some kinking in the backdrop transitions (indicated by the white arrows):

Perhaps the can be fixed by moving the screws farther in (the black arrows). This may be a complete non-issue, so you be the judge.

Regarding clouds, you might want to check out these videos:

I think they both show that really effective clouds are not hard to achieve, but that they do require some time. I think that the Yarnell video highlights a really important "technique" for us non-artists...have a photo in hand to guide the process.

Check Google Images for clouds ( blue sky clouds, clouds panorama, cumulus clouds, etc.,etc.) set them close and paint the cloud you see!

Thanks so much for sharing your adventure.

David Stewart

Kinks

One thing I definitely noticed was that my placement of the screws in some spots forced a sudden transition from curve to flat.  This happened in two types of areas:

1) On the 1"x2" pieces.  For those, it causes a flattening of the curve over the flat surface of the wood in the midst of a curve.  These are not really noticeable, but a more smoothly flowing curve could have been achieved by using round stock instead of 1"x2" pieces so the only point of contact was at the intersection of the curves. 

2) In places like those shown where I was transitioning from curve to straight contact with the plywood.  I can think of two approaches that would have avoided an issue there.  One would be as suggested to move the screws further away from the apex of the curve.  But I suspect it would have to be quite a distance from the apex of the curve to totally eliminate the issue.  The other thought would have been to use a wedge and simply make sure the screw placement matched the natural contact point between the wedge and the curve so that again the screw would be truly perpendicular at the point it passed through the FRP.  (A curve transition piece of wood top and bottom might be even better than a wedge, but would require very careful planning and cutting whereas a wedge would likely work fine if screw placement was right.)

In my case, once the valance and scenery are in place, I think all the kinks will be hidden.  I may also play with loosening the screws a tad or shifting them as suggested to see if that helps the situation.  

Thanks for the cloud painting videos, too!

-Ed