Monday, October 6, 2014

Foiled by poor quality

I am going to vent a little here so please stand back....

So you remember several months ago I showed you a picture of the nice new plenum I had purchased from Sam James?  I re-posted the picture below that shows the plenum in all its glory sitting on the fuselage of the airplane.  Well this weekend I decided it was time to get the plenum fitted to the baffles.  I figured that the quality and attention to detail that went into the cowling should be true for the plenum as well, right?  Well let me tell you that it is not even in the same class.  The plenum does not even come close to being usable as it is.  So, I have read in a couple of other builder blogs about how others had the same issues but I (incorrectly) assumed that the product would improve with time (as the cowling has).  Wrong.  I have rarely seen such poor quality in an aviation related product.  It is not even remotely of the same quality and workmanship that the cowling and induction system are.  Will James (North Shop) makes the cowling and induction system and I have commented a couple of times in the past about how much I enjoyed working with him.   He has been extremely helpful and his products are top notch quality.  Sam James (South Shop), maker of the plenum, is very experienced, knowledgeable and a joy to listen to during his composite forums at Oshkosh.  So I expected a lot from his products.  Let me show you in pictures what I dealt with all weekend long.

Ok, so here is the plenum (orange piece sitting on the engine) as I begin the fitting process.  The only thing I have done to the plenum at this point is spend way too much time grinding down rough edges, seams and places where excess fiberglass strands had protruded.  This is where my "quality of product" concerns started.

Here the plenum is after I had made my first cut to get it to fit.  Note that I chose to make this cut because the form of the plenum did not fit my engine block (the one it was designed for).

Here you see the beginning of the metal baffle section that I decided to fabricate on the front of the engine.  I can form this a little better and then use red RTV on the back side to eliminate any air gaps.  Remember I said earlier that since this is an air cooled engine I need all of the available air to be used in cooling the engine, not escaping through holes where it does nothing but create drag.

Here you can see where I had to cut the left aft edge of the plenum off.  It did not fit...not even close.  I will have to fiberglass a new recess cover and since my oil cooler will get its cooling air from this section of baffle I need to make some other modifications to it.

Ok, yet another round of cutting on the plenum here.  As you can see I have pretty much removed the entire front center section.

Here are a few of the pieces I had to cut off the plenum.

Another good example of the quality of product I am talking about.  See that nice groove down the middle of this piece?  Well this is a seam where two pieces were joined together.  You can see the layers of glass on the back side to make the part strong but on the front it was only partially filled with what I assume is gel-coat.  You can see the darker orange where the thickness of the stuff is very deep.  That said if you look at the groove you will see there was a huge void under the top layer of gel-coat.  I found several areas with voids like this.  Some air will always get trapped in a fiberglass layup but wouldn't you think that these should be filled with micro or better yet flox?

I'm not sure what to think of this.  See that dark reddish spot?  Well, its a pool of the epoxy or gel-coat.

Ok, final picture in my rant post....  This is my way of forming a lip that will seal against my forward baffle material.  This grey stuff is clay that I am molding and will lay some fiberglass over to form the lip.