This follows from the "Roof clip dimension?" thread where the discussion progressed from my question about the diameter of the Promaster's roof clips.
The little posts are inconsistent in diameter which may just be paint. I used a letter F drill and found that to be tight in 8 out of 8 posts.
My first set of roof rack mounts did not satisfy. They work fine, but I wanted to mount Rich Solar 200 Mega panels from side to side directly on 1-1/2 inch angles attached right to the clips as forward/aft rails. The problem was that the holes for the nuts on top of the mounts would be badly placed in the panels' frames. This could be solved by mounting the off center or by using a tube to raise the panels above the nuts. I didn't want to go higher.
These are the main pieces of the mount:
![Image]()
What is not shown:
Parts of the rack.
2 rails 1-1/2 x 1-1/2 x 1/8 Alum sharp corner Angle 144" could vary in length
2 crossbars 1-1/4 x 1-1/4 x 1/8 --ditto-- to fit inside and on the rails
1 head board 2 x 1-1/2 x 1/8 --ditto-- the width of the entire rack
2 head screws 1/4-20 x 1/2 stainless hex caps
@ 25 1/4-20 x 3/4 --ditto-- for mounting panels, bars and rails
@ 16 1/4-20 x 1 --ditto-- for mounting through the top-plates
@ 41 nuts and washers for above
If I had planned slower the top plates might have been 2-3/4 inch wide.
The rail length of 144" allows room to build a fairing in the front (I'll probably never make one). So one could get a couple inches to the front. And my rack ends about over the middle of the roof's back radius. All the crossbars are filed to fit exactly.
I put a dot on the center of the posts so I can see that my clips are centered on them. Put the clip on the post; slide the double-nut into it, check that you can get a screw, with anti-seize, into the double-nut; place the pad around it. If a clip is not clearly below its pad's top you have a problem. Place the top-plates, and with ANTI-SEIZE, fasten them loosely. Place the angles on top; get one side all lined up. The front end of the front top-plate should match the angle's. Then just snug them. For the other side I used two dead-sticks to set the rails to fit the panels with a 1/8 inch to spare on each side.
Against later movement, mark around the pads. The last thing to do
is to goop 295uv to the sides of the mount bases, allowing water to flow through front to back.
![Image]()
Notes:
This is a light weight, light duty rack. If I planned to put weight in the back, I would have put the rails inside a heavier larger angle from the back to the third mount. Then the top plates could be thinner in the rear or the forward part shimmed. The aft two crossbars would also be larger. On mine , there is only about 8 sq ft for cargo and that is split by the fan.
The cross bars clear the roof by 1/2 inch. This makes the 1/8" clearance for the panels necessary for access. Dealing with the panel cabling is done by loosening the bolts on the far side; lifting the panel's near side enough to wedge them 3-1/2 inch above the rail
for access to goop the cabling to the roof.
![Image]()
With the low height, this wrench came in handy for about 5 of the panel bolts. When put into use, I quickly came to appreciate that the wrench was about 3/64" over the nominal 7/16". It is from 12 ga. hot rolled steel.
It was somewhat tedious to get the bolts down through the panels and rails.
Rustoleum products were used to paint the aluminum, primer, satin white and clear coat. Their 5 in 1 spray nozzles are good against painting nothing. In New England humidity, the paint was soft for days, but it has hardened in the weeks since.
Not finding a non-flapping way to put a safety line through all the panels, I put two 6" beads of 295uv on each edge of the panels.
Stainless rolled threads are common on bolts and nuts, but machined stainless threads are very quick to seize to rolled or machined. So antiseize.
![Image]()
The little posts are inconsistent in diameter which may just be paint. I used a letter F drill and found that to be tight in 8 out of 8 posts.
My first set of roof rack mounts did not satisfy. They work fine, but I wanted to mount Rich Solar 200 Mega panels from side to side directly on 1-1/2 inch angles attached right to the clips as forward/aft rails. The problem was that the holes for the nuts on top of the mounts would be badly placed in the panels' frames. This could be solved by mounting the off center or by using a tube to raise the panels above the nuts. I didn't want to go higher.
These are the main pieces of the mount:
- 1-1/2" thick mounting PVC pad
- 3/4" square x 1/8 wall alum tube 3" long cut to fit roof post & 9/32 holes on 2" centers
- 1/8" x 0.490" stainless bar with 1/4-20 holes on 2" centers
- 3/8" x 3" x 11" alum bar w/ 5 1/4" countersunk holes on 2" ctrs 1" from a side
What is not shown:
- Stainless flat head screws to fasten top plate
- Anti-seize !
- Sita 295uv for bedding to roof.
Parts of the rack.
2 rails 1-1/2 x 1-1/2 x 1/8 Alum sharp corner Angle 144" could vary in length
2 crossbars 1-1/4 x 1-1/4 x 1/8 --ditto-- to fit inside and on the rails
1 head board 2 x 1-1/2 x 1/8 --ditto-- the width of the entire rack
2 head screws 1/4-20 x 1/2 stainless hex caps
@ 25 1/4-20 x 3/4 --ditto-- for mounting panels, bars and rails
@ 16 1/4-20 x 1 --ditto-- for mounting through the top-plates
@ 41 nuts and washers for above
If I had planned slower the top plates might have been 2-3/4 inch wide.
The rail length of 144" allows room to build a fairing in the front (I'll probably never make one). So one could get a couple inches to the front. And my rack ends about over the middle of the roof's back radius. All the crossbars are filed to fit exactly.
I put a dot on the center of the posts so I can see that my clips are centered on them. Put the clip on the post; slide the double-nut into it, check that you can get a screw, with anti-seize, into the double-nut; place the pad around it. If a clip is not clearly below its pad's top you have a problem. Place the top-plates, and with ANTI-SEIZE, fasten them loosely. Place the angles on top; get one side all lined up. The front end of the front top-plate should match the angle's. Then just snug them. For the other side I used two dead-sticks to set the rails to fit the panels with a 1/8 inch to spare on each side.
Against later movement, mark around the pads. The last thing to do
is to goop 295uv to the sides of the mount bases, allowing water to flow through front to back.
Notes:
This is a light weight, light duty rack. If I planned to put weight in the back, I would have put the rails inside a heavier larger angle from the back to the third mount. Then the top plates could be thinner in the rear or the forward part shimmed. The aft two crossbars would also be larger. On mine , there is only about 8 sq ft for cargo and that is split by the fan.
The cross bars clear the roof by 1/2 inch. This makes the 1/8" clearance for the panels necessary for access. Dealing with the panel cabling is done by loosening the bolts on the far side; lifting the panel's near side enough to wedge them 3-1/2 inch above the rail
for access to goop the cabling to the roof.
With the low height, this wrench came in handy for about 5 of the panel bolts. When put into use, I quickly came to appreciate that the wrench was about 3/64" over the nominal 7/16". It is from 12 ga. hot rolled steel.
It was somewhat tedious to get the bolts down through the panels and rails.
Rustoleum products were used to paint the aluminum, primer, satin white and clear coat. Their 5 in 1 spray nozzles are good against painting nothing. In New England humidity, the paint was soft for days, but it has hardened in the weeks since.
Not finding a non-flapping way to put a safety line through all the panels, I put two 6" beads of 295uv on each edge of the panels.
Stainless rolled threads are common on bolts and nuts, but machined stainless threads are very quick to seize to rolled or machined. So antiseize.
