KEEPING THE MICE OUT OF THE DOG HOUSE Mike Hausner · KEEPING THE MICE OUT OF THE DOG HOUSE Mike...
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Transcript of KEEPING THE MICE OUT OF THE DOG HOUSE Mike Hausner · KEEPING THE MICE OUT OF THE DOG HOUSE Mike...
KEEPING THE MICE OUT OF THE DOG HOUSE
Mike Hausner
Photo #1
This spring while getting ready to work on the buggy I discovered that over the winter I had a
couple of unwanted guests take up residence in the garage. More specifically, in the cooling shrouds
of the VW engine. Photo #1 is not a very good picture but you get the idea. They can get in through
the engine air cooling inlet or the gaps between the cooling shrouds and engine block. I planned to
seal up all these entry points. As an added benefit this should also improve engine cooling.
Since my engine has aftermarket tin, it has gaps where the shroud is supposed to seal against
the block. This may not apply to engines using original equipment shrouds.
Photo # 2
To close up these gaps I fabricated aluminum pieces with a mounting tab. The tab will have a
RIV-NUT (or NUT-SERT) installed. These little gems allow you to add a threaded boss to thin sheet
metal parts. They work something like a pop rivet. Photo #3 shows the RIV-NUT installed on one of
the blocking plates.
Photo # 3
I used cardboard to mock up each blocking plate until I was happy with the fit of each part,
then I made an aluminum copy. A hole was then drilled in the cooling shroud and the location
transferred to the aluminum part. This hole was then enlarged to fit the RIV-NUT . You need a
special tool with a threaded stud that goes into the RIV-NUT. It’s the same idea as the pop rivet gun
except its reversed. Instead of the pin going into rivet gun, the threaded stud is on the gun and goes
into the “rivet”. You squeeze the handle and the RIV-NUT deforms and is clamped in place as in
photo # 3. In photo # 4 you see how the plate effectively seals the gap. Photo # 5 shows the three
completed blocking plates needed to seal the gaps on my engine.
Photo # 4
Photo # 5
The cooling air inlet is another opening that needed to be looked at. I had a screen to cover
the air cooling inlet but it was made to fit the early design cooling shroud. The early housing is flat on
the back and it is pretty easy to mount a screen to keep out debris and uninvited guests. The newer
design moves the oil cooler toward the front of the car and out of the airstream going to cylinder
number four. But you probably already know this.
In photo # 6 you can see the different levels on the back of the “dog house” cooling shroud. It
is NOT FLAT. My first thought was to make an aluminum bracket that would follow the contours of
the housing. How hard can it be? Well, my one “bracket “soon became three and I soon decided
that aluminum was not the way to go.
Photo # 6
I decided on FIBERGLASS. When making a part or mold with ‘glass you need to have some
way of removing the part without destroying it. The professionals use a liquid parting agent called
PVA (Poly-Vinyl-something or other). Since I didn’t have the recommended stuff (PVA) I had to use
the next best thing - SARAN WRAP.
The area around the air inlet was to be covered with the plastic wrap to act as a parting agent
for the fiberglass piece. This is not as easy as it sounds as the SARAN WRAP does not like to
cooperate. I finally had to use a spray adhesive on the plastic wrap and this made things somewhat
easier but it was still difficult to place where I needed it.
Photo # 7
Once the plastic wrap was in place I cut several pieces of fiberglass mat and cloth so that I had
enough to cover the area around the air inlet at least three times. The pieces are positioned one at a
time and saturated with resin using a paint brush. Pieces are added around the opening until there
are at least three layers of fiberglass mat and cloth. The cure time varies with the amount of
hardener and the ambient temperature. Due to the cold temperatures at the time I had to use a
work light to add a little heat to help the cure the part. My part was fully cured in about 6 hours.
After initial trimming I decided the part was a little flimsy so I added another layer of cloth to
the outside. In photo # 8 you see the trimmed part with the added layer of glass cloth.
Photo # 8
After final trimming and fitting I marked and drilled the first of three 1/8” pilot holes. I
installed a CLECO in the first hole and proceeded with the second and then the third. The CLECO’s are
a sheet metal clamping device used in aircraft manufacturing and are very handy when working with
parts like this. Photo # 9 shows the part held in place with three 1/8” CLECO’s. With the holes
located I drilled the housing for the RIV-NUTS.
Photo #9
The final step is to apply plastic wrap (again) to the dog house and using a liberal amount of
aquarium grade RTV, attach aluminum screen to the backside of the fiberglass part. With this done
the assembly is then fastened to the housing using three 10-32 screws.
Photo # 10
Here you see the finished part. This should keep the mice out of the dog house. Any
questions or comments you can e-mail me at: [email protected]