It's a busy day! A couple of new questions!

[muddog16]

I believe this is the most I've used the board ever!   First question, to those that changed over to a Williams air throttle, what did you do with the fast idle solenoid, do you still use it, and if you do how, or did you remove it?

Second question,  to the body specialists, where I installed my new fiberglass caps, they over lap the aluminum skin, is it possible to use bondo or(what is the correct material) to bring these two different body parts into one smooth surface, that won't crack later?   I'll post a picture of this area below.  As always thanks!

[Dreamscape]

Pat, Can't help with the air throttle, but on the cap this is what I used, Duraglass. It's a type of body filler with filberglass fiber. It's easy to use like Bondo, mix in some harderner, slap it on a small area at a time and sand it down. It's really tough stuff, feather the edges and finish it off. Go down to your trusty auto body paint shop and see what they have.

I checked out your site, again, really cool work you have done. I'm amazed at how clean you are able to keep it! And all in your driveway too, in between snow and rain.

[luvrbus]

Pat, the fast idle has nothing to do with the throttle from the skinner valve the line goes to the holding cylinder to a tee on the holding cylinder then down to the fast idle cylinder are you using a Jake that could change if you don't have the fast idle Jake cylinder.
For the crack in a flush mounted cap with 2 different materials no matter what you use it will crack at the seam over time I noticed I have a crack on mine now we all fight that and it is worse when you are equipped with leveling jacks these old girls will twist and flex.


good luck

[muddog16]

Thanks Paul, I'll look for that duraglass! 

Clifford, I've run a 3/8" copper line for the air throttle, on the prevost there is a fast idle solenoid and a stop solenoid.........using the Williams air throttle will I need the fast idle?  Yes I have Jakes.  On the Prevost there is a air piston that is actuated by the sol, it pushes the idle arm a fraction for fast idle, with the Williams air throttle will I need the fast idle?  There is a picture of my air throttle on the engine below!

[bevans6]

As far as the body work is concerned, I would embrace the change, unless it is horrible.  then, as little as possible of the matt-filled bondo stuff, or several layers of cloth/resin fiberglass and then a skim of bondo.  Surface prep is  critical, at least an 80 grit or coarser finish well developed anywhere that filler will touch, and I use acetone as a final prep cleaner.  I use an epoxy resin for this, West Systems brand is what I use, not typical polyester.  It is far better for bonding to dissimilar substrates.


Brian

[luvrbus]

Pat, the one on top is not the fast idle that holds the throttle the fast idle goes where the buffer switch for the Jake's screws into the governor housing if you don't have a cylinder with a micro switch built on a cylinder about 1 1/2 ins around 3 inches long with a air connection you have no fast idle  sorry I can't post photos for you.post a photo of you buffer switch

good luck

[muddog16]

Clifford I do have that buffer switch, it came off of the old engine!   I wondered what that was.....lol!  Ok thanks I'm learning!

[muddog16]

Here are some more photo's of my air throttle and the old cylinder that isn't installed!

[Just Dallas]

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[muddog16]

Dallas that is what my original question was, I wasn't sure if I either wanted it or better "needed it"!

[Jeremy]

The trick to bonding aluminium to glassfibre is to bond to the aluminium itself, not the oxide coating that very quickly forms whenever raw aluminium is exposed. Epoxy is essential for bonding of this sort - polyester just won't do the job. Even if you do get a perfect bond, though, it will still crack if there's any relative movement between the two pieces, or if the two materials flex differently.

If it were me I would probably choose to 'embrace the change' as has been said:- if the fibreglass is on top of the aluminium, no amount of filler is ever going to make the joint flush anyway - all you can hope to do is spread the difference in levels out over a larger area, which might make things look worse than having an obvious step. If the step you have is unsightly due to being uneven then perhaps cover it with a moulding of some sort.

Jeremy

[Dreamscape]

Also different materials heat/cool/expand/shrink at different rates. Good advice from posts above!

[eddiepotts]

I bet it helps having that spider to get in those tight spots for ya,

[muddog16]

Eddie, I saw that spider but was to late to save him from the evil detroit diesel monster!

[Just Dallas]

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