Quattro Mod.....

[Wolvie]

Hi all,

Just wondering if anyone knows of a good blackboard paint to apply on the back and edges of the Pyrex mirrors on the quattro as I find it reflexs alot of light and I saw someone using blackboard paint as it has a very low reflecting property?

I will also be using Protostar Flocking in the tube so would like to get it all done in the one go

Thanks in advance,

Pat

[sbooder]

A mat permanent sharpie is better for that, it is easier to wield than a brush.

[Singlin]

I painted the sides of my Primary and scondary mirrors of my quattro with a grey colored black board paint.

I regret doing it though as it needs to come off before you send your mirrors to be re-coated.I also painted the inside of my focuser tube and outside. THe spider vanes etc etc.

Any black board paint will do.

[JamesF]

Be aware too that just because it's black doesn't mean it isn't reflective in IR or UV.

James

[Martin Meredith]

Another option is to make a combined fan holder and light excluder as shown in one of AstronomyShed's youtube videos. That's what I did for my Quattro. It's basically a plywood circle with an inner circle cutout for the fan, and 3 notches cut around the edge to allow access to the collimation knobs. It simply attaches with velcro to the metal ring where the collimation knobs are. It excludes any light from the rear without having to paint the primary. Of course, you can do it without the fan by not cutting the central disk out, or add the fan later if you decide to.

Martin

[Wolvie]

Thanks for all the replies would using the protostar flocking be any better then?

[Singlin]

I flocked the inside of the tube as well as black board paint.

[Martin Meredith]

I forgot to say that you can also flock the mirror facing side of the light excluder. I used the stuff from Wickes. I've yet to flock the rest of the Quattro though...

Martin

[Uranium235]

Another option is to make a combined fan holder and light excluder as shown in one of AstronomyShed's youtube videos. That's what I did for my Quattro. It's basically a plywood circle with an inner circle cutout for the fan, and 3 notches cut around the edge to allow access to the collimation knobs. It simply attaches with velcro to the metal ring where the collimation knobs are. It excludes any light from the rear without having to paint the primary. Of course, you can do it without the fan by not cutting the central disk out, or add the fan later if you decide to.

Martin

Good tip there.... its surprising how much ambient light can leak in through the bottom of a newtonian ota. My cover is just a bit of cardboard with notches cut our for collimation, took all of 60s to make.

[Wolvie]

Thanks all for the replies, I am making a cooling fan for the Quattro just waiting on the parts to come I will post the parts list and prices and a link to how I went about making it.

and I will post pictures of where I was planning on painting the mirrors as it's like frosted glass and it seems to bounce the light a bit. but more product research is needed me thinks, as I would be worried about the paint flaking or bubbling.

Pat.

[triton1]

The flocking material I had left I put on the back of primary and then painted the sides with blackboard paint,then painted side and back of secondary then painted secondary holder and focuser tube and well everything inside the tube,nuts ,vanes etc.Its surprising that when you shine a torch down the ota the nuts,screws etc still reflect even though their factory black.

[Wolvie]

The flocking material I had left I put on the back of primary and then painted the sides with blackboard paint,then painted side and back of secondary then painted secondary holder and focuser tube and well everything inside the tube,nuts ,vanes etc.Its surprising that when you shine a torch down the ota the nuts,screws etc still reflect even though their factory black.

 

Thats what I thought, TBH and that was the main plan of action. As a test the other night I called over to the parents house with it (as they live in a housing estate and would exagerate any stray light sources) and was shocked at how much of this was showing up.

[laser_jock99]

Good tip there.... its surprising how much ambient light can leak in through the bottom of a newtonian ota. My cover is just a bit of cardboard with notches cut our for collimation, took all of 60s to make.

Very true- I looked down the tube of my 8" one night back at the lit house windows and was horrified at how much light was visible. I made a black, drawstring 'hoody bag' to go over the end!