Plastics for Construction Or What?

[W7WV]

I was looking in the hardware store the other day for some plastic that might hold up for the center feed for dipole construction.
I found that with the price of petroleum so high that many plastics are also very high in price.
I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
I don't know how this is going to hold up to UV but it's pretty cheap material and easy to cut and shape. I think it's made of recycled material but I am not sure.
My dipoles are all on pulleys so I can raise and lower them so if it does not work out it's easy to change them out.
Maybe others could post some materials they have used here that could help others out too.

[A71AN]

Quote[/b] (W7WV @ June 30 2007,09:45)]I was looking in the hardware store the other day for some plastic that might hold up for the center feed for dipole construction.
I found that with the price of petroleum so high that many plastics are also very high in price.
I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
I don't know how this is going to hold up to UV but it's pretty cheap material and easy to cut and shape. I think it's made of recycled material but I am not sure.
My dipoles are all on pulleys so I can raise and lower them so if it does not work out it's easy to change them out.
Maybe others could post some materials they have used here that could help others out too.
My friend I could not really understand why is the plastic for the dipole is needed, forgive me for my ignorance and if possible to you explain why the plastic is needed, please ?

Thank you my friend

73

[W7WV]

For the insulator for the center feed. I attach my feed wires, coax or ladder line to the insulator.
I have used the ceramic or porcelian eggs in the past and some prefabed stuff they sell.
I have also seen people use PVC plastic pipe and ABS drain pipe for antenna construction too but they don't hold up well with our extreme UV here in AZ.

[A71AN]

Oh, I inderstand now my friend, thank you a lot.

I used to use, some sort of electrical insulators and worked well, it also takes the hard time of the weather conidtions and remain good for long years.

Thank you again my friend and wish you and yours all of the best

73

[KI4ITV]

PVC "T"s work well and they're cheap too. http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

[KC9JIQ]

Quote[/b] (W7WV @ June 30 2007,09:45)]I was looking in the hardware store the other day for some plastic that might hold up for the center feed for dipole construction.
I found that with the price of petroleum so high that many plastics are also very high in price.
I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
I don't know how this is going to hold up to UV but it's pretty cheap material and easy to cut and shape. I think it's made of recycled material but I am not sure.
My dipoles are all on pulleys so I can raise and lower them so if it does not work out it's easy to change them out.
Maybe others could post some materials they have used here that could help others out too.
I've been thru the same situation, I am amazed being the 21st century that a farm store does not stock nylon or any workable plastic whatsoever.

I ended up using a nylon kitchen cutting board, from Wal-Mart, to make my heavy duty antenna ball mount insulators.

Not even the supply houses could get nylon, steel and aluminum yes, nylon or any machinable plastics, no.

The thing was it was a Friday evening, about 3p.m. and I needed the nylon for a weekend project.

About the only place that would sell nylon is a Machine shop in another town, or I would have to mail order it.

[W3MIV]

I think your cutting board will work out very well. You might want to spray paint it with a black enamel, which will tend to help minimize and UV problems. I would give it a couple of coats, letting each dry thoroughly before recoating. The black also minimizes visibility, which is often a nice side benefit.

Given the size and thickness, you should be able to make up several substantial center insulators so that, even should the weather and UV take its toll, you will have a number standing by as replacements.

GL with your project. Let us know how it comes out.

[W7WV]

Visability is not a problem here. I have acreage with no antenna restrictions whatsoever so far in the county.
I had a tower/beam up and like a dummy I took it down when I thought I was getting out of the hobby. I will put another up someday. I still have a 5' square chunk of concrete in the ground to support a free stander if I need it.
And it's interesting how hardware and farm supply stores have changed over the years. Stuff we used to buy that was always there has disappeared for good.
In Corporate America if the product does not generate so many dollars per sq ft they dump the product. Sad but very true.

[WA9SVD]

Plexiglass or LEXAN © are used in outdoor applications, so that material should work quite well, and a "glass" shop might have scraps (suitable for insulator use) for little or no money. It will probably withstand exposure (heat, rain, cold, sun) as well as most materials, since it's used in skylights, windows, etc. and those don't normally disintegrate from UV the way some plastics do. But check with a local electronics shop if you can; a porcelein (ceramic) "dog bone" style insulator will last longer than you or I, and be reusable by another generation of hams after that.

Not knowing exactly what plastic is used in the cutting board you bought, there's no way to predict it's longevity in an outdoor environment, even if painted for protection.

(Actually, PVC pipe is used for irrigation and sprinkler systems, and ofter exposed to sun and elements. The thick wall Schedule 40 with appropriate "T" , short sections of 3/4 or 1" pipe and end caps SHOULD stand up to the elements for at least ten years. If it works here on the Sunny Left Coast, it should work well even in Arizona. In fact, a number of commercial antennas and baluns ARE manufactured using standard schedule 40 PVC plumbing materials.))

[ka0gkt]

Go to your local farm store (Tractor Supply Company, Orscheln, Wheeler's, etc.) and obtain some electric fence insulators. They're inexpensive, readily available and work well for wire antenna insulators.

73 DE KAØGKT/7

--Steve

[W7WV]

Hey I never thought of that!

[ka0gkt]

Quote[/b] (W7WV @ June 30 2007,12:56)]Hey I never thought of that!
They Have Farm Stores in Hereford? http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

I know that they're available in Sierra Vista. #I saw some when I was picking up some hardware for the KUAT/KUAZ translator site on TV Hill.

I discovered electric fence insulators back in teh late '70s or early '80s. I used to purchase them at a local place back in Nebraska called "Diers Supply". I think that Orschln's bought them out a few years back..

73 DE KAØGKT/7

--Steve

[wd0ct]

Many cities have plastic supply houses. Of course they have plenty of scrap sizes of different plastics.Check the yellow pages.

[wd0ct]

What a coincidence. On the q&a forum there is a thread right now about farm and home homebrew with some cool electric fence insulators - cheap.

[W7WV]

Sure we have a couple of places that have farm stuff and feed and such out off of HWY 92 just South of Sorry Gulch~sorry been calling it that since I first came here in the Army in 1967. They even changed the name of one of the bars I used to go to to the Sorry Gulch Saloon.
I tend to forget these store are there as I tend to hit Home Depot, Ace now Lowe's new store.
Has anyone besides me ever notice that these newer corporate type stores have less and less of what do it yourself types want? I sure have!
Give me an old fashioned hardware store or farm supply for that matter any old day!

[ka5piu]

Hello.

I get bullet proof plastic as scrap from some places that work with that stuff.
I fabricate super heavy duty clip boards out of this stuff that have arm bands.
The clip boards are just big enough to cover the vital areas or the head.
I make them as the material becomes available and they are normally only supplied to our security forces.
But, one was left on top of a fuel storage tank in Saudi Arabia, one of the first, in 1983.
It was recovered last year.
It was upside down all this time so the sun was at it full force.
It is a bit yellow, but, to test it, a 7.62x39 round was fired at it from 333 Feet.
It worked as intended.
So, it is the quality of the plastic.

[N3ATS]

Quote[/b] (W7WV @ June 30 2007,11:45)]I was looking in the hardware store the other day for some plastic that might hold up for the center feed for dipole construction.
I found that with the price of petroleum so high that many plastics are also very high in price.
I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
I don't know how this is going to hold up to UV but it's pretty cheap material and easy to cut and shape. I think it's made of recycled material but I am not sure.
My dipoles are all on pulleys so I can raise and lower them so if it does not work out it's easy to change them out.
Maybe others could post some materials they have used here that could help others out too.


http://n3ats.com/?Homebrew_Stuff:PVC_Dipole_Center_Insulator

[N2RJ]

Quote[/b] (W7WV @ June 30 2007,14:56)]Hey I never thought of that!
How come? They're recommended by quite a few antenna books.

[W7WV]

Because until I returned to ham radio a few years ago after retirement all I ever did was work on the antennas the Navy had.

[KI4NGN]

Quote[/b] (W7WV @ June 30 2007,13:34)]Has anyone besides me ever notice that these newer corporate type stores have less and less of what do it yourself types want? I sure have!
Give me an old fashioned hardware store or farm supply for that matter any old day!
As the population has exploded, the number of DIY types has imploded.

Corporate America has always been. Stores carry what sells. Shelf space costs money. Why would a store stock something that they might, just might, sell a couple of times a year?

Those old hardware stores and farm stores carried what they sold. As it has always been, if someone needs a 'something', it is likely cheaper for a store to order more than one, and the additional becomes stock.

Those older stores are fast disappearing for a reason; they can't compete with the stores that operate much more efficiently on a larger scale. One of those efficiencies is the management of shelf space.

And as with everything else, there's a cost. In this case it's the loss of finding those seldom sold items on the shelf.

If you enjoy purchasing items for less out of pocket expense than you could from a smaller store, then it's progress.

If you can't find what that smaller store used to stock, it's a loss.

This is why Radio Shack went to hell. Not to start yet another RS debate, but they were faced with either going out of business, or re-inventing themselves to try to stay in business. There just weren't enough people coming in to purchase CBs, SWL receivers, electronic components, etc, etc, for them to stay in business.

Some people had a store loyalty and would make their purchases from smaller stores even though the prices were higher. Most people, understandably, shop by price, causing the demise of any business that can't compete with those prices.

Mike

[W4HAY]

I've had good luck with MFJ's ceramic insulators (http://www.mfjenterprises.com/products.php?prodid=MFJ-16C06). They're less than a buck each.

Check their website, they also may still carry the 'egg' strain insulators.

[wb6mmj]

Quote[/b] (W7WV @ June 30 2007,09:45)]I was looking in the hardware store the other day for some plastic that might hold up for the center feed for dipole construction.
I found that with the price of petroleum so high that many plastics are also very high in price.
I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
I don't know how this is going to hold up to UV but it's pretty cheap material and easy to cut and shape. I think it's made of recycled material but I am not sure.
My dipoles are all on pulleys so I can raise and lower them so if it does not work out it's easy to change them out.
Maybe others could post some materials they have used here that could help others out too.
A friend of mine used two flat pieces of plexiglass, laying one on top of the other, for the center insulator. He used a router to carve out, on both pieces, a place for the coax to go up inside and a place for the wire to come in and connect to the coax. Holes were drilled to hold the wire in place. and other holes were drilled to hold the two pieces of plastic together. The two pieces are sealed with caulking. This keeps the connection points out of the weather and dry.
Next time I have to bring down my inverted V for 40, I`m doing what he did. We live in snow country here and It`s a good way to go.

[cu2jt]

Quote[/b] (W7WV @ June 30 2007,09:45)]I finally found a polymer kitchen cutting board that is 8"x10"x 1/4" in size for $2.
That would probably be HD Polyethylene, which is an excellent isolator, resistant to most chemicals but might be affected by UV radiation. The mechanical properties are not the best - this is a soft but tough material.

The best plastic for isolators is PPO (Polyphenylene Oxide). It has excellent dielectrical and mechanical properties and has a low density, about 1.2. Only PTFE (a.k.a. "Teflon") has better dielectrical properties but is very soft, heavy and very expensive. Polystyrene is also a good isolator but can be hard to find in slabs and rods and has poor resistance to UV radiation.

For HF, PVC would do but the losses can be extensive on VHF/UHF. Watch out for black PVC (or any other plastic). It has good climate properties but the black pigment is usually semi conducting carbon stuff.

Avoid "Nylon" which is hygroscopic. Also, Polymethyl-metacrylate (a.k.a. "Plexiglas") which will crack in cold weather and is also sensitive to UV radiation.

[n3ef]

Quote[/b] (cu2jt @ July 01 2007,20:01)]Avoid "Nylon" which is hygroscopic.
Absolutely no need to avoid nylon for a dipole insulator. It is considered hygroscopic, and in general, nylon can absorb 8% of it's weight in moisture if totally immersed. This can cause the dimensions to change as it absorbs and then releases moisture but this is really of no concern in this situation.

#I use nylon flex-weave and budwig center insulators to make my dipoles. No other insulators required, no knots to tie, and easy to trim the dipole when tuning.
http://home.comcast.net/~fairbank56/dipole.html

Eric N3EF