Flocking a Newtonian - Slightly Easier Method

[Ratlet]

Well the kids are going to be home for Easter which basically means that today is the last chance I have for flocking my Dob till after Easter.  I figured I'd document the method I use, which is advised by the late, great @johninderby and is a brilliant way to keep a handle on the flocking material without it sticking to itself.  The basic idea is to make a template of the inside of the scope (holes and all) out of plastic then stick the flocking to that.  This avoids the joy of trying to stick large sheets of sticky material to the inside of a tube.  It's especially useful for smaller Newtoians such as the 130PDS since it can be hard to get space to work on the inside of the tube on that scope due to the smaller aperture.

Today I am working on a StellaLyra 10" Dobsonian. 

Additional materials:

• some flocking material (enough to do the inside of the scope, it doesn't have to be a single sheet.
• A plastic poster cover big enough to do the whole tube, or at least most of it.  I used A0 for this and it wasn't quite big enough.  It's not a big deal though.
• Some masking tape (or sticky tape if like me you can't find yours which was right here 5 minutes ago)
• A craft knife
• A Hole punch or drill. (Not required but makes it easier)
• Some doublesided tape (May not be required).

The first step is to remove the fittings.  In this case I removed the mirror cell (be careful), the top tube ring, the focuser, secondary and the finder shoe.  I did not remove the altitude pivots as I am weak and could not get the screws out.

The next step is to slide the poster tube inside the OTA.  I like to use the weld to line everything up and one end of the scope to make sure that everything is straight and true.  Use bits of tape (masking tape prefered) to secure the plastic in place.  You want to make sure that everything is snug against the walls of the tube.  A Good tip here is to see if the top ring will fit over the top of the plastic.  In my case it did, in other cases like my 130PDS it didn't.  If it does, do everything flush with the end of the tube.  If it doesn't you'll need to put the top ring back in and do everything flush with this.

Secure it at the ends of the tube as well to make sure it is flush.  You want to make sure it is secured at both ends.

The next step is to go around and mark all the holes and where you need to cut.   Make sure that you are careful here.  Measure twice, cut once.  We can now remove the plastic from the tube and cut it.

Be careful and take your time.  I used a hole punch for the smaller hole and a knife to cut out the larger holes.

Now the tricky bit.  Stick the flocking to the plastic.  It helps to get a hand here.  Take your time and try and avoid air bubbles.  IF you get them and can't get rid of it you can pop it and squeeze the air out.  If like me you need more than one bit, try and get a small overlap.  Doing it on a large flat area is much easier than sticking it to the inside of a tube.  I stuck mine to the textured side of the plastic in the hope that it will provide better adhesion.  I also ended up with a small overhang.  I left the protective plastic on this as we've already established the plastic is too small for the tube in this case so this will help cover the gap.

Next step is to give the flocking a quick hoover to removing any loose fibres and grub from it. 

After this you can install the flocking in the tube.  In my case I used the front end ring and the primary mirror cell to hold the plastic, an alternative would be to use double sided tape.  The small gap which can be seen here can be quickly covered with a thin strip of flocking.  I put mine in with an overlap to make sure none of the paint was visible. 

After this you can reinstall all the jewellery, get the secondary in and collimate with your preferred weapon of choice.  I could probably have flocked the focuser, but I don't think it is critical and I needed to pick up the kids.

 

So that is basically it.  I think it is easier than trying to stick the flocking to the inside of the tube.  Especially if you have a smaller Newtonian or are not an octopus, although your mileage might vary.  Hopefully this will help someone out!

[Ratlet]

The finished product:

 

[josefk]

Good effort - neat trick!

[bosun21]

I am thinking about flocking my 12” but would most probably do it the conventional way. Slow and steady gets the job done in my book. This is a good method to avoid the wrinkles and bubbles, not to mention the swearing fits.

[Louis D]

Also good for flocking the rear baffle tube of Maks and SCTs.

[PeterStudz]

18 hours ago, bosun21 said:

I am thinking about flocking my 12” but would most probably do it the conventional way. Slow and steady gets the job done in my book. This is a good method to avoid the wrinkles and bubbles, not to mention the swearing fits.

When I flocked the whole of my 8” Dob I thought about doing the method mentioned here but bit the bullet and decided on the conventional way of just sticking it down.

And I was surprised how well it went. Easier and far quicker than I thought. And no swearing fits - honest! The flocking material wasn’t as sticky as I expected and any “errors” I was able pull it away and stick it down again. I did find that a head torch helped (it’s dark in there) and flexible hands and wrists. Any bubbles were easily removed by pricking them with a needle then rubbing down.

As I had everything apart I even flocked the inside of the focuser draw-tube. Not sure if it’s necessary but it was literally a 5 minute job.

Edited March 31, 2023 by PeterStudz

[DaveL59]

I did similar when I refurb'd the little TAL-M following @johninderby's lead, esp as the TAL tube inners can be a difficult surface to adhere onto, not to mention its a pretty narrow tube to try to work in. I was concerned the flock might lift away and droop given my scopes sit in the conservatory which gets quite "warm" so to counter that possibility I also tacked the flock to the plastic with needle and thread, just in case. Worked a treat, simply slide the plastic into place and refit all the bits and enjoy the results 🙂 

[Spile]

No issues with the black velour just sticking it directly to the tube without using templates.