Large Scale Central

New Deck Girder Bridge for Indian Hill

Track and Trestles
#101

I was home from work early Thursday. Temps were in the 70’s with very low humidity. I sat on my butt at the computer instead of getting back to work on this project. Today the temps are rising and so is the humidity - for some reason I was motivated to get to work on the aluminum “girder”. First I used my miter saw to cut the tube to length…

Next, I used the table saw to chop out the landing areas for the abutments on either end…

Once the cutting was complete, I used my ‘DA’ sander with 220 grit to scuff up the aluminum to give some tooth for epoxy and primer. Also shown in this shot is the slice in the center of each side to simulate two bridge sections…

The end cuts were filed smooth and then hit with the DA…

Finally, both ends are ready for some PVC filler to close up the extrusion and create the proper height above the abutment…

I’m going to try and do the next steps indoors as the weather is not going to improve untill late next week, but before I get much further I need to do a test fit on the abutments. I’ll hide in the air conditioning for an hour or so before giving that a try :smirk:

#102

I got outside just before the thunderstorms rolled in, pulled the old bridge and droped in the girder for a test fit. It’s GOOD!

The West (down grade) abutment is a bit off level. I’m not sure if I will try and straighten it, or just shim the girder. The test track on wood ties lines up pretty good too considering they will end up higher by two thicknesses of styrene…

The East end is about perfect. This is good to know since I made about a 1/4" error in cutting the ends. If I hadn’t made the error the girder would have been too high…

#103

So the 1/4 inch error made it fit properly? Thats not an error in my book. Thats great foresight in compensating for whatever variables came into play. In other words, you meant to do that. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#104

Sure I did! First pass on the saw the kerf was on the wrong side of the line, so I adjusted by 1/8", but went the wrong way. Once it was done there was no going back. I figured I’d just cover the opening with 3mm PVC rather than .020 Styrene. The real error was in estimating the depth of the shelf on the abutments. I did it with the bridge in place and was “sure” the old bridge was 3/4" ply. In reality, it was probably 1/2".

So yes, I was clairvoyant and knew that I had screwed up by 1/4" when surveying the abutments.

#105

Hehe…nice!

#106

Daktah John said:

Sure I did! First pass on the saw the kerf was on the wrong side of the line, so I adjusted by 1/8", but went the wrong way. Once it was done there was no going back. I figured I’d just cover the opening with 3mm PVC rather than .020 Styrene. The real error was in estimating the depth of the shelf on the abutments. I did it with the bridge in place and was “sure” the old bridge was 3/4" ply. In reality, it was probably 1/2".

So yes, I was clairvoyant and knew that I had screwed by 1/4" up when surveying the abutments.

Ats whut I said. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#107

I cut the styrene strips for the simulated top and bottom angle tonight. Was going to glue down a few to the aluminum tube, but my 4 year old 5 Minute Epoxy is hard as a rock. So much for buying a 5 year supply! (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-frown.gif)

#108

**Daktah John said:**4 year old 5 Minute Epoxy is hard as a rock. So much for buying a 5 year supply! (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-frown.gif)

#109

Yea, glues are best fresh, so I quit buying the “economy size”.

#110

While I’d like to agree with you David, in reality it just doesn’t make financial sense to buy the small quantities. I went to Lowes this evening. A half ounce tube of 5 Min. Epoxy was $5. Looking at the size of the tube I estimated I’d need three or 4 at minimum. An 8 ounce set in bottles was $15. So even if I end up throwing it away in 3 or 4 years, I will still have saved money.

It’s just frustrating to throw away a bottle that’s more than half full. This time I will not rely on the wimpy cap closure. When I’m done I’ll put some Saran Wrap under the lid. Perhaps that will extend the life a little.

#111

Drawing from my ancient handy tricks; We used to store paint bottles upside down. The theory being the contents would seal the lid and keep air out. IIRC channel locks helped opening them later…

Might could oughter try it with the poxy, whaddya think?

John

#112

John, no I don’t buy the micro sized bottle neither. And I don’t buy my glues at the LHS, and pay 10 times as much per ounce. I also don’t tend to buy the jumbo size, unless I am starting a large project.

I hate throwing out stuff, but what really gets me aggravated, is starting a project, and then finding out the glue I wanted to use has turned into a rock. This discovery usually happens about 3 min before Lowe’s closes, so I have to stop the project until the next day.

#113

Good thought John C., but I would have to find some flat caps. The bottles come with pointy caps to dispense the liquid.

Got the first few feet of styrene that simulates the angle along the top and bottom of the girder attached tonight. Will finish to the center tomorrow and take a few progress pics. Need to order some angle for the verticals.

EDIT to add: Re storing upside down: I suppose I could make a rack with holes or store them upside down in the box they came.

#114

Some store there glues in glass jars.

#115

The heat wave broke a bit today so a work extra was called out to the west abutment to see about leveling it up. First order of business was to excavate enough to see what the problem is, and allow the block to move…

It seems the tree is once again the problem. This root grew pushing the block up on one side…

When I started, the block was out of level by about 3/4 of a bubble. With the edge of the block supported with some concrete scrap as sown above, I was able to lift the other side bringing it level again. To hold it in place, a few strips of 3mm PVC were wedged in the crack between the block and the wing wall. The wing wall is very stable as it has rebar deep into the ground…

A long shot of the work area before back fill…

Dirt and rocks were replaced and some ballast added to dress it up…

Looking at the picture above I think that once the new detailed bridge is in place this will be another great photo spot. From above…

Final level check…

Foreman George says that he’s satisfied the area is now suitable to lay in the new bridge…

The shop crew just needs to get busy and finish welding up the girder!

#116

Looking good John. I have to agree with the great looking area for photo’s. Even the work crew photo’s look great.

#117

Womens Work!

(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

#118

Daktah John said: When I’m done I’ll put some Saran Wrap under the lid. Perhaps that will extend the life a little.

Is there a chance that wrinkles in the wrap would make tiny channels for air to get in?
As for the girder cutting, call it the irony of being serendipitously erroneous. Or, simply, way cool! :smiley:

#119

Maybe Forrest. I could use some self-adhesive vinyl - I’ve got lots of that.

#120

One place where I used to work would store their super glue in the freezer. Once it warmed up to room temperature, it worked just fine. I know photographers would store their unused film in the refrigerator, it extended its shelf life. So maybe you could store your glue in the fridge, right behind the beer. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)