Pipe Insulation and Truss Poles

[John]

I'm planning on getting some black foam pipe insulation to cover the truss poles of my Lightbridge 12" dob. Armaflex seems to be the best available and it's black rather than grey as other brands seem to be. The truss poles are 25mm in diameter but the Armaflex comes in 2 bore sizes, 22mm and 28mm. My current thoughts are to get the smaller of the two and hopefully the foam will stretch a bit to fit over the slightly wider tube - does that sound feasible ?. I'm going for the 9mm wall variety so the tubes are not too fat once it's fitted.

Maybe if there are any plumbers out there who have used Armaflex (for plumbing or astro use) they could let me know it thats the right choice.

If I had settled for the ordinary grey stuff I'd buy a metre and try it but Armaflex is much more pricey and I'd rather make the right choice up front if I can.

Thanks,

John

[Chris Stacey]

I don't think you'll have any problem with the 22mm, I used a slightly smaller diameter with insulating some outside pipes. That said, I wasn't using Armaflex. The 28mm wouldn't fit to well I wouldn't have thought, I'm sure they'll confirm that for you if you give them a quick bell to see how much "give" the 22mm has in it.

[John]

Thanks Chris

John

[Chris Stacey]

No worries. I'd like to see it when it's done.

[FLO]

Consider also the foam tape supplied for bicycle handlebars, its self adhesive so easy to fit and it looks neat.

[TheThing]

There was a thread about this before somewhere (I seem to recall?? Maybe I'm just dreaming!)

Have you thought of bicycle inner tubes? Much more flexible and also much thinner - will not protrude into your area of view at all.

I'm sure a local bike repair shop would be happy to give you their old ones for free as you don't need them to be air tight. Cut to length, maybe a lenght ways seam to ease putting them on and Bob is etc etc...

[G4YVM]

If you leave the truss poles shiny and bright, what happens? I appreciate they might create light problems, but do they actually do this?

And I imagine they can be chilly to hold on a cold night.

I ask this because I am building a 16" Dob and had intended to leave the truss poles brightly polished. the cold can be dealt with with gloves.

D

[johninderby]

Have you considered this?

http://www.heatshrink-online.co.uk/heatshrink/prod_338706-254mm-Black-Heat-Shrink.html

or this?

http://www.heatshrink-online.co.uk/heatshrink/prod_340434-25mm-Black-Expandable-Braided-Sleeving.html

John

[John]

Thanks for all your advice and ideas folks

I've ordered some black foam insulation with the thinnest wall I could get (9mm) so I'm hoping that will do the trick - I'll report back on how it goes.

As the truss rods are not in the light path I guess the potential for them to cause unwanted light scatter is slight but as many people seem to blacken them I thought I would do the same if I can find a simple way to do it. Of course the Astrozap light shroud I bought from FLO a few weeks ago is the has made a big difference to keeping unwanted light out of the tube - I'm expecting any further blackening to have a minimal effect TBH.

I notice some folk have blackened the inside of the tops and bottoms of the tube sections which is white inside and out in the Lightbridge - is that a worthwhile mod ?.

John

[John]

No worries. I'd like to see it when it's done.

Here you go (the last ones a close up of the counter weight system I've fitted):

[JAO]

John

Scope looks excellent with the insulation on the poles. Can I ask where you got the insulation from? I am looking for some for a DSC Stalk project. Decided the Markless was too pricey so have made my own using 25mm ali tube.

Adrian

[John]

Hi Adrian,

After a long search which revealed nothing but the standard grey stuff in DIY shops I was tipped off by a fellow SGL member to look out for Armaflex pipe insulation which is matt black. I eventually found it being sold by a central heating supplier who also sells through e.bay - there are a few that do it on there. It's not cheap but it's great stuff. It needs to be applied with some care - it's not split so it needs to slide on and it will tear on sharp projections. I went for the 22mm bore with a 9mm wall which fits my 25mm truss tubes like a glove and does not project into the light path. The Astrozap light shroud is a snugger fit now though - but fine.

Hope that helps.

John

[JAO]

John

Many thanks this is really helpful, I have a look at ebay and go for the same dimensions you used as the tube I have is 25mm.

Thanks

Adrian

[Chris Stacey]

Here you go (the last ones a close up of the counter weight system I've fitted):

I'd forgotten about this thread, hence I didn't see your reply. My bad.

It looks great John, ties it all together nicely.

I take it the slightly smaller diameter of Armaflex was the way to go? I want to do the same to some tripod legs, so I want to get it right.

Edit - obviously the smaller diameter is the way to go as I've just seen you've already covered that lol. Did it have much give in it, or is it a really tight fit?

[John]

....I take it the slightly smaller diameter of Armaflex was the way to go? I want to do the same to some tripod legs, so I want to get it right.

Edit - obviously the smaller diameter is the way to go as I've just seen you've already covered that lol. Did it have much give in it, or is it a really tight fit?

Only just found this post Chris - sorry for the delayed reply.

I went for the 22mm bore x 9mm wall Armaflex in the end. The fit was snug but it slipped on to the truss rods smoothly - from the end with the rounded flat bracket rather than the squared off end - the latter would tend to tear the Armaflex.

I'm very pleased with the result

John

[The Warthog]

This is a bit of a naive question, but why not paint the truss poles flat black?

[John]

This is a bit of a naive question, but why not paint the truss poles flat black?

Good question WH - painting was certainly another option but I went for the Armaflex because it was less messy, almost as cheap (total cost was around £15) and, frankly, quick and easy to do - once I had sourced the right insulation.

John

[calibos]

So his tongue doesn't stick to a frozen truss pole??