Wednesday, August 22, 2012
Monday, June 11, 2012
Saturday, May 19, 2012
Sunday, August 21, 2011
Friday, July 23, 2010
Repairing the subfloor
So, I read a lot of internets. The minute I get home with a new project (usually from Craigslist Houston) I search the googler for web forums that cater to whatever tool or vehicle or livestock animal I just bought. Its a series of tubes. Its not a big truck.
A basic search for the group dedicated to Airstreams will lead you quickly to the Airforums. It is a HUGE group of AS owners that have posted a lot of info. A little digging around and I had all the info I need for the subfloor fix. Most AS resto's are what the old timers call "The Full Monte". Which is removing the shell completely from the frame and floor. We're not taking this trailer on the road so I am comfortable with just replacing the rotten places and leaving the rest of the original floor intact. So lets get started.
The first thing you have to do is cut out the old stuff. It takes at least three tools to get it out if are not removing the entire shell. You need a Circular saw, sawzall, and angle grinder with a cut off wheel. First thing is to set the depth of cut on the circ saw to just a hair deeper than the thickness of the floor. You don't want to cut into the steel trailer frame below. The 1973 has a layer of insulation between the frame and the floor so you get a little wiggle room which is nice. Make a plunge cut with the circular saw and make the cut as close to the fuselage as you can get. The sawzall will get you the rest of the way.
In the pic I am using a Fein Multimaster but the blade broke and I finished the job with a Sawzall and it was soooo much easier.
Once the rotted stuff is removed you need to measure the holes you just made and cut pieces out of new plywood to replace them. The curves of the AS make this a little complicated so I'll walk you through my method. Here's the hole we need to fit:
I laid out the lines I needed to cut the way you lay out lofting lines on a boat from a set of plans. I measured the length of the hole and the width at the widest point. I wrote these figures down for later. Then I measured along the length, starting at the point (or the narrowest part) and put marks along the edge of the original subfloor every three inches. These marks are called lofting stations. At each mark, I then measured the distance from the end of the original subfloor to the exterior panels of the fuselage. Each measurement was longer than the last, producing a curve that matches that of the skin.
The marks on the bottom of the board are the corresponding lofting stations to the ones I measured inside. This is a template and not the final piece. To get the curved edge transferred to the template, make a mark at each station according to the measurements you took from the AS. Now make a line from dot to dot which should look a lot like the curve you are after. I want mine to be really tight so I am taking it one step further.
First I cut the template along the lines I just drew. I bring the template back into the bus to get a more accurate curve for the final piece with a scribing tool called a Perfect Butt.
To scribe a line, you simply lay your template against the curve you need to fit. Then you run the scribing tool along the wall, leaving a mark on your board.
You can see the poor fit of my first rough cut in the template. There is a lot of room inder that interior skin though so I could porbably get away with using this piece. But I'm trying to learn new skills so on this day, I am making a much tighter fit.
Here is the PB scriber in action. That line is going to be transferred to the final piece and carefully cut out with the jig saw.
Here we are tracing the template curve to the final piece.
And cutting the final piece.
And finally, the completed pieces are in. I pretty much followed this recipe with all of the parts. I did it somewhat like a jigsaw puzzle which I'm sure is not the right way to do it.
A basic search for the group dedicated to Airstreams will lead you quickly to the Airforums. It is a HUGE group of AS owners that have posted a lot of info. A little digging around and I had all the info I need for the subfloor fix. Most AS resto's are what the old timers call "The Full Monte". Which is removing the shell completely from the frame and floor. We're not taking this trailer on the road so I am comfortable with just replacing the rotten places and leaving the rest of the original floor intact. So lets get started.
The first thing you have to do is cut out the old stuff. It takes at least three tools to get it out if are not removing the entire shell. You need a Circular saw, sawzall, and angle grinder with a cut off wheel. First thing is to set the depth of cut on the circ saw to just a hair deeper than the thickness of the floor. You don't want to cut into the steel trailer frame below. The 1973 has a layer of insulation between the frame and the floor so you get a little wiggle room which is nice. Make a plunge cut with the circular saw and make the cut as close to the fuselage as you can get. The sawzall will get you the rest of the way.
In the pic I am using a Fein Multimaster but the blade broke and I finished the job with a Sawzall and it was soooo much easier.
Once the rotted stuff is removed you need to measure the holes you just made and cut pieces out of new plywood to replace them. The curves of the AS make this a little complicated so I'll walk you through my method. Here's the hole we need to fit:
I laid out the lines I needed to cut the way you lay out lofting lines on a boat from a set of plans. I measured the length of the hole and the width at the widest point. I wrote these figures down for later. Then I measured along the length, starting at the point (or the narrowest part) and put marks along the edge of the original subfloor every three inches. These marks are called lofting stations. At each mark, I then measured the distance from the end of the original subfloor to the exterior panels of the fuselage. Each measurement was longer than the last, producing a curve that matches that of the skin.
The marks on the bottom of the board are the corresponding lofting stations to the ones I measured inside. This is a template and not the final piece. To get the curved edge transferred to the template, make a mark at each station according to the measurements you took from the AS. Now make a line from dot to dot which should look a lot like the curve you are after. I want mine to be really tight so I am taking it one step further.
First I cut the template along the lines I just drew. I bring the template back into the bus to get a more accurate curve for the final piece with a scribing tool called a Perfect Butt.
To scribe a line, you simply lay your template against the curve you need to fit. Then you run the scribing tool along the wall, leaving a mark on your board.
You can see the poor fit of my first rough cut in the template. There is a lot of room inder that interior skin though so I could porbably get away with using this piece. But I'm trying to learn new skills so on this day, I am making a much tighter fit.
Here is the PB scriber in action. That line is going to be transferred to the final piece and carefully cut out with the jig saw.
Here we are tracing the template curve to the final piece.
And cutting the final piece.
And finally, the completed pieces are in. I pretty much followed this recipe with all of the parts. I did it somewhat like a jigsaw puzzle which I'm sure is not the right way to do it.
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