yes, a 15FT painters poll would be fairly strong, though I wouldn't want to 
have it raised while your going down the highway at 75MPH!
another type of fiberglass poll is a poll used for doing concrete work.  I 
don't know what they call them, but they come in different lengths, and are 
telescopic...and very strong.
The other consideration is that you don't want that antenna sticking up more 
than 2 feet above your roof line while your mobile.  Bridges and other 
considerations prevent you from having something more than 14 feet from the 
ground...unless you don't mind replacing the screw driver after each trip hi 
hi.
So, one must assume that you want something that you can erect when you are 
stopped?
Or, as you say, something telescopic so you can easily pull or push it up 
when you are stopped.
The linemans poll is great for that because it comes in 5FT sections.  You 
just get up on the top of the latter and pull each section up at a time 
until they click together.  Then, when you are ready to bring it down, you 
just depress the spring pins until each section is lowered again.
Of course, the linemans poll is hollow, but the tip is generally solid, so 
running a ground wire down the center of the poll might be a bit difficult.
A painters poll would be plenty strong enough to support the screw driver or 
even a tripple hussler type configuration, while you are stopped.  Once it 
is lowered down for travel, it will be extremely strong with all the 
sections pushed together.
Perhaps make a trip to your local hardware store and see what they have in 
stock for telescoping polls.  There are allot of jobs that require that sort 
of thing, so they're more common than you might think.
Several weekend HF ers around here use painters polls to support both 
vertical mobile antennas, and for wire supports in a field or camp ground.

73
Colin, V A6BS
----- Original Message ----- 
From: "Tom Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, August 15, 2011 8:06 PM
Subject: Re: Need suggestions for better mast arrangement to safely raise HF 
screw-driver antenna on RV


>        Good point, Colin.
>
> Now, I'm starting to think of something like a painter's pole, although I
> wouldn't think the normal ones would be strong enough.
>
> Will keep thinking on this for sure, so keep those suggestions coming!
>
> 73 de Tom Behler:  KB8TYJ
>
> ----- Original Message ----- 
> From: "colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, August 15, 2011 9:54 PM
> Subject: Re: Need suggestions for better mast arrangement to safely raise 
> HF
> screw-driver antenna on RV
>
>
>> yes, but you can always run a wire down the non-conductive pipe/tube if
>> necesary.
>> 73
>> Colin, V A6BS
>> ----- Original Message ----- 
>> From: "Tom Behler" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Monday, August 15, 2011 7:52 PM
>> Subject: Re: Need suggestions for better mast arrangement to safely raise
>> HF
>> screw-driver antenna on RV
>>
>>
>>>    Pat:
>>>
>>> I thought of that, but wonder if it would be strong enough.
>>>
>>> Also, it may not help me couple the antenna to ground, as John suggested
>>> earlier.
>>>
>>> 73 from Tom Behler:  KB8TYJ
>>>
>>> ----- Original Message ----- 
>>> From: "Pat Byrne" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Monday, August 15, 2011 9:44 PM
>>> Subject: Re: Need suggestions for better mast arrangement to safely 
>>> raise
>>> HF
>>> screw-driver antenna on RV
>>>
>>>
>>>> How about PVC?
>>>> Pat, K9JAUAt 09:00 AM 8/15/2011, you wrote:
>>>>>Hi, all.
>>>>>
>>>>>Well, I attempted to check into yesterday's 20-meter Cross-Country 
>>>>>blind
>>>>>ops
>>>>>net from the RV, but was not successful.
>>>>>
>>>>>I believe my screw-driver antenna simply is not high enough on the back
>>>>>of
>>>>>the RV to allow me to get out well.
>>>>>
>>>>>The antenna is mounted with u-bolts on the back bumpber on a piece of
>>>>>pipe
>>>>>that is probably about thre or four feet high.  This gets part of the
>>>>>screwdriver antenna and whip above the roof line of the RV, but it does
>>>>>not
>>>>>get it completely above the roof line by any means.  The RV is
>>>>>approximately
>>>>>12 feet high.
>>>>>
>>>>>Originally, I had used an arrangement with a longer piece of mounting
>>>>>pipe,
>>>>>but it turns out that the pipe was de-tuning the antenna, especially on
>>>>>10
>>>>>and 15 meters.
>>>>>
>>>>>So, my question is this:  Does anyone know of a fiber-glass or other
>>>>>type
>>>>>of
>>>>>non-conductive mast that I might try to get the screw-driver up higher?
>>>>>Obviously, I want to be safe here, and don't want to have to mess with
>>>>>guys.
>>>>>
>>>>>Something telescopic might be the best, but again, I would think it
>>>>>would
>>>>>have to be of fairly high quality.
>>>>>
>>>>>If anyone has any suggestions, I'll save them for future reference.
>>>>>
>>>>>Due to a number of other things going on right now that will put a 
>>>>>crimp
>>>>>in
>>>>>the budget, I probably won't be able to do anything until next year's
>>>>>camping season, but it's always good to start thinking and planning in
>>>>>advance.
>>>>>
>>>>>73 from Tom Behler:  KB8TYJ
>>>>
>>>
>>