flocking a dob

[sunshine185]

I am thinking of flocking my dob ,has anyone used blackboard paint instead of the self stick material? I know I am going to have to remove the spider and secondary, is this easy to do? I presume I just unscrew the four nuts holding the spider veins, is this true? Any help would be appreciated

[Moonshane]

I'd take out the primary and secondary assemblies and the focuser. just make sure you don't drop anything and you'll be fine - it will teach you about collimation!

I used the stuff from FLO - better than Protostar as it has some 'allowance' (to lift off and restick) if you get it wrong.

[Moonshane]

if you struggle just ask.

[jimmyjamjoejoe]

Blackboard paint wont be much different to whats in there already. As moonshane says, take everything out, its all pretty self explanatory.

There is a guide to flocking on cloudy nights which got me through it, the one that recommends using clothes pegs to hold it in place and peel the backing off an inch at a time.

It IS fiddly, like trying to stick sellotape to the inside of a straw. Just make sure you measure and cut very straight, then you can be sure that if it lines up with the top of the tube, it'l be straight everywhere else etc. I had to peel off the second sheet a couple of times after getting half way round and it went back on fine.

Took me an hour or so to do the tube and focuser, and reassemble.

[sunshine185]

The four nuts holding the spider veins, do I undo one at a time and remove it or do I have to undo each one a little at a time? Also, regarding the focusser, if I put flocking material inside the draw tube and outside where it protrudes into the ota, does it all still fit back together easily enough?

[Steve Ward]

Just be aware that the secondary is relatively heavy for its size , make sure you have a good grip on it .

And have the tube laying horizontal so anything that gets dropped doesn't go careering down onto the primary.

[sunshine185]

K, chaps thx for the advice.

[johninderby]

Here's a guide I wrote a while ago that may be of some use.

John

Flcoking 200P OTA.pdf

[Steve Ward]

Use the blackboard paint on the O/S of the focuser tube but don't paint the bits that need to slide , they're obvious when you get there.

And this may help .

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=19&t=7788

[studdedsole]

Go to the trouble of flocking - you won't be dissapointed it is worth the effort

[sheridangj]

Hi,

I've literally just flocked my 200P dob today! I used the Cloudy Nights guide referred to earlier - I would say this told me all I needed in a lot of detail from start to finish. Disassemble your OTA in this order: primary mirror, top tube ring, spider/secondary (I counted the turns as I unscrewed each thumbscrew - 9 for each, and turned the same number of times when replacing), finder bracket, focuser and lastly alt bearings. It was easier than I expected to take apart, rebuild and collimate but applying the flocking paper was quite a stressful experience! I did a reasonable job in the end (not too many air bubbles!) but if I did it again I would cut the paper into smaller strips to make it easier to apply - I was trying to keep the number of joins to a minimum but in doing this I think I just made it harder for myself. It's so black in there now you can't see the joins anyway! Now I just need this weather to clear so that I can go out and admire the results!

Hope that helps.

Gav

[Steve Ward]

If you get a bubble just make a small incision in it and squeeze the air out as you press down from the edges , narrow scalpel works wonders.

[sunshine185]

My 10" has arrived fully flocked, here is a comparison with my 8" unflocked dob

[8kids]

Can you get longer rolls of flocking material? My newt is a bit portly round the middle and I'd rather not have a patch work quilt effect inside.

[sunshine185]

Would this be big enough http://www.wilkinsonplus.com/dc-fix-fablon/d-c-fix-original-deco-self-adhesive-film-velour-black-348-0005/invt/0309578/?htxt=lzgxpbCvLUafU5sM8Cil%2FW57D9WGCBWpRKScjLS4auY047NalhZIOCfTOVOM3QClrUrZFLSY2riU%0A%2BuN%2FaAMPfg%3D%3D

[Moonshane]

your 300 will have a circumference of about 1m and I think the rolls from FLO are that too? I tend to do mine around the circumference rather than down the length if that makes sense?

[8kids]

The circumference of the tube is about 1.15metres a 1m roll is just short.

[Moonshane]

ahh, sorry, the OOUK tubes I have are quite a bit smaller then. to be honest it does not matter really as you cannot see the joins when in the tube.

[jimmyjamjoejoe]

Either way you're gonna have to make joins. I think you can order specific lengths of protostar but you'l pay for it.

[8kids]

Patch work quilt it is then.