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Sectioned and Channeled Pocher Alfa Spyder

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28 minutes ago, kpnuts said:

Amazing work going on here.

Thank you kpnuts


2 hours ago, Codger said:

Soooo good to see you back David. Brilliant work.


A masterclass on correcting an out-of-box train wreck!


Correct me if I'm wrong; weren't the cowl louvers cut out and new correct ones installed?

Thank you, Chas


The stock louvers will be replaced after the cowl has been sectioned to reduce its height.  You can see the process on the first  body at the top of page 2, a May 16th post.

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D'ya know what!?  I totally hate plastic, but it's a proper buzz watching what you guys do what you do with the stuff. Hat's off to everyone who's willing to "go- the-extra-mile"......you have my FULL respect!!!!!!!!!!

Keep up the good work!


Cheers, H

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In my second June post, on page three, you see that I saved the rear edge of the cowl so that the molded edge could be re-used on the modified cowl.  The recessed molded edge will be covered with leather.


Below you see the cowl prepared for installation and the trailing edge.





After removing the rear section of the cowl, the new rear edge is narrower, so the molded edge has to be cut to fit.  A 7mm section was removed.  The trailing edge of the cowl on this body will be more than 5mm narrower than that of the first body I built.  This is closer to the dimension of the prototypes.  This is why I used this method to reduce the length of the cowl on the second body.





The two pieces were "welded" to the cowl with solvent and Milliput and Evercoat body putty were applied to fill the seams, saw cuts, and to level the panel.


Below are two work-in-process photographs.  Much sanding, filing, and at least one more application of putty lie ahead.


Also, you can see the kind of sophisticated tools you need to build a Pocher. 










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I know for a fact how difficult it is to make a slender cut on a compound, reflexed curve - superb work David.


When I pie-cut my Rolls roof, sectioned the doors (first set) and chopped and sectioned the trunk, I could have used a chain saw in comparison to this work. This is master surgery.


I know that when complete this model will look perfectly 'natural' (and accurate) meaning it will be impossible to know how much of this work went into it just by viewing it. Unless side-by-side with a stock Pocher Spyder. It is imperative that one save a pictorial record such as this and back it up on disc. We all know what happens when trusting third-party servers.

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Thanks, Chas.


It helps to have the right tools.  I have shown my flush cut saw in previous posts, but it's probably worth showing it again.  


A flush cut saw is used to cut dowels flush with a wood surface without damaging that surface.  The saw is thin, flexible, and the teeth have no "set" .  My saw was made in Japan, so it cuts on the pull rather than the push stroke.  The blade is 0.3mm thick.


Because it is so thin, because it cuts on the pull stroke, and because it can cut while it is bent, it is ideal for model making.  Because the teeth do not protrude on the sides, I can position the saw with precision by letting the teeth slide against a fingernail. 


Photographs below show how thin the blade is and that the teeth have no "set".






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30 minutes ago, CrazyCrank said:

Is it a Tamiya saw, Endeavor ?

I own this last one, which is 0.27 mm thick and very accurate when cutting :)


I purchased the saw several years ago from Garret Wade to use on a wood working project.   I have a few Tamiya tools and they are all excellent.

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To reduce the height of the body to more accurately reflect the prototypes, the cowl was sectioned  7.5mm.


Below you see the procedure I used on the  first body I built.   Because I shortened the cowl by removing a vertical section from the entire cowl, I only sectioned the forward section of the cowl.  The rear section of cowl and the rear of the body were channeled, lowered over the frame and trimmed 7.5mm on the bottom edge.





 Because I used a different procedure to shorten the cowl on this body, this time I removed two sections from the entire length of the cowl, from the leading edges to the door openings.


The first step was to mark off a A 7.5mm section in the center of each of the two side louver panels.








Below are two work-in progress photographs.  The cuts were again made with my flush cutting saw.







The louvers were removed as they are too tall and poorly formed.   Sectioning the cowl also starts the preparation for building smaller louvers.


You can see the process of building proper louvers on the second page of this thread.  





The four cuts are complete and the two parts are held together temporarily with clamps.






The two parts fit together well, but the joins, the leading edges, and the door openings all require work and the connection between the upper and lower sections will be reinforced on the inside with styrene sheet.





Below are the four 7.5mm sections that were removed.



Edited by Endeavor
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A most clever method on the height reduction to body and cowl. A central trim to the cowl and an equal cut to the main body lower edge. Well thought-out.


And Jeroen's right - your prose is beyond descriptive and a joy to follow. I will be the first to order the build journal book when you publish...😎

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Wow! Dave, I really have been out of the loop for way too long! I’m getting ready to start my F-40 back up and along with it I’m going to start up my Alfa Monza. Chas mentioned that you had started your thread on your Alfa back up and, I can see that, you have been VERY busy! I’m going to have to go back and read this whole thread and pay attention to the work that you did on the frame and placement of the engine and radiator and make the necessary changes to my frame. Thanks for the dedicated detail work on this Alfa, it will be a great reference for myself and every other Alfa builder. I can see that I’m going to have to take a few days in order to get back up to speed on both of my Pocher builds before, I even pick up a tool. 

I’m not sure when or if I will post anything about the Alfa but, since the Ferrari thread is already started I will eventually start updating it when I start making some progress. In the meantime I’ll continue to steal, err borrow, your ideas and techniques to try and make my Alfa better. Keep up the great work and I’ll be following your progress on this great car. I know just how bad these Alfa’s are warped and all the problems with the kit and unless you have ever worked on one you can’t imagine the fit problems. A Tamiya kit it’s not!

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So, I’m in the middle of getting caught up on the Alfa and I see that you moved your engine back 10mm and I know that adds extra work to modify a few other parts that connect to the engine and transmission etc. Given everything that you are doing with the body, a few extra things probably won’t make much difference in your build. 

I’m thinking about a more modest 3-5mm move which would accomplish the radiator to fan clearance and reduce the amount of extra modifications. 

I also have the MMC springs and I have been told that the mounting locations for the front and rear springs are incorrect on the Pocher frame; did you encounter that and if so what did you do to correct it? 

In reading this newly started thread you have already done the springs and I was wondering if that was in the original thread? I can’t seem to find your first thread and even though it’s picture free now I am curious if this something that you discussed. 

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I don't want to go too off topic so I will try to answer your questions briefly.  If you send me your email address, I will send a few more photographs and more detailed explanations.  I can also send you a PDF of the original thread.


I would move the engine back 10mm.  It is not that difficult, particularly for someone with your skills.  The move is important both for aesthetics and for historical accuracy, particularly for the Monza.


Because Pocher made changes over the course of the production run(s), because of variable quality control, and due to variable conditions under which the models have been stored over the years, there are often considerable differences in the kits today.  My comments are accurate for the kits I have built.  Also, it is important to note that there are builders more ambitious and expert than I.


My Monza kits did not have significant warps.  There were asymmetries that were simple to fix.  The two big issues I found were that the bodies did not fit properly on the frame and that the rear tank is inaccurate.  I also modified the rear skirts to match the particular prototypes I wanted to emulate.


The photograph below shows how I modified the body so it would fit the frame.  I posted a thread detailing the process on another web site several years ago.  


I removed the seat, made two diagonal cuts, and properly positioned one of the resulting two pieces on the frame and taped the other to the rear tank.  When positioned correctly, the two pieces of the body were separated by two gaps, each 1.5mm wide, with almost perfectly parallel edges.  I filled the gaps with styrene pieces.  The body now fits perfectly without the use of fasteners to hold it in position.





I modified the tank, adding "wings" to the bottom to match some of the prototypes.  To properly emulate the tanks of the prototypes is a major undertaking which I did not attempt.  Others have done this better than I.





Here is a better look at the modifications I made to the rear skirts.  You can study photographs of prototypes to see which Monza you want to emulate.  The complication, of course, is that many photographs are of recently built replicas rather than originals.





You can see the changes I made to the springs and their mounting points on page two of this thread.  I haven't looked at this for a while, but my recollection is that the mounting points for the springs on the Pocher Monza are accurate enough.  The Spyder kit utilizes the Monza frame, which makes it inaccurate.  Both kits have front and rear suspension systems that position the frames too close to the ground.  In addition, because the front suspension positions the the frame higher, the frame tilts upward toward the front.  The changes I made to the my Spyder frame solved this problem.  The problem will have a be solved differently for the Monza. The clearances for the front suspension components are very tight and there is little room for upward suspension travel.


The prototype Spyders I have been able to study all have asymmetrical front and rear springs.  I believe that the Monzas have shorter springs that are also symmetrical 



Edited by Endeavor
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I just went back in my messages folder and found where you and I talked about this before and I have your email address. It's just been sitting so that I forgot. I will send you an email as you suggest so that, I can get the info offline and keep the K73 build on topic. Sorry guys, now back to our regular programming! 😯

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It is not obvious from the photographs, but I spent hours with sandpaper, files and Evercoat in an attempt to perfect the shape and surface of the top of the cowl .  I also applied two more layers of 0.13mm styrene sheet to the inside of the cowl to add strength and to clean up the surface.  The interior surface of the cowl must be prepared for the leather that will be applied after the body has been painted.


In the photograph below you can see some evidence of the surface work that has been done.  The pencil marks define low areas that required more putty. 


The remaining louver was removed from the top section of the cowl and a piece was removed to achieve the correct horizontal dimension for the opening in the top section of the cowl.





This photograph provides a fairly good illustration of the work-in-process.





The remaining sections to be removed have been marked.





This photograph reveals that cutting the cowl for the leading edges of the doors earlier was a big mistake.  New leading edges of the jambs will be built with styrene after I make mockups for the new doors.  The shape and dimensions of the doors can be determined only after I lower the bottom of the door jambs to the correct height and lower the rear body, aft of the doors, to the correct height.  The good news is that Pocher put the rear door jamb in the   correct position relative to the firewall, frame, and rear axle.





After the surgery.









To strengthen the connection between the two pieces of the cowl, holes will be drilled to accept 1.2mm steel rod.  The first two holes were drilled with the pin vice.





The steel pin inserted into the bottom section.  The pin is 10mm long.





The steel pin in position.





And the result.  The next step will be to drill six more holes for three more pins.  Then all the joins will have to be adjusted a bit, welded, more Evercoat, and sanding.  Finally, styrene sheet will be applied to the insides of the joins to add strength and rigidity.



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That's some excellent and secure joinery there.


You obviously don't need tips from me David but here's a couple that have worked well for me.

For finding those low spots in filler I've used the guide coat method which I'm sure you're familiar with. A thin mist dark lacquer coat and very light sand with maybe 400 or 600 grit brings them right out.


Alternately, a thin coat of Future brushed on allows seeing any waviness in the reflection of bright light. The Future self-levels and removes with iso. Sand if you prefer. It's also a good barrier on raw filler for priming. No matter, it's evident you will make these surfaces perfect.


A question about the upholstered cowl; would it not be better to make patterns of the areas (especially under curves) from thin sheet or cardstock , then upholster those and finally glue those in place?





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Thanks, Chas


I had not thought about using Future.  I'm not yet trying to achieve a perfect surface.  I'm just trying to get the major cowl dimensions and adjustments right before beginning next major surgery.  I only need to get it to the point where it can provide accurate reference points for the work that comes next.  The task of perfecting all the surfaces will come when all body panel modifications are complete.


I do plan to upholster a styrene pattern(s) for the area under the cowl, but I have to clean up the underside of the cowl so the template will fit as smoothly and as closely to the reinforced body as possible.

Edited by Endeavor
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The two cowl sections were "welded" with solvent.  


I installed the four 10mm steel rods to minimize the possibility that the panels would flex a bit at the joins which could later create  cracks in the paint.  I did not anticipate that the rods would dramatically increase the rigidity of the cowl.  They did.   Mounted on the frame, it is almost inflexible. 


The joins were finished with Milliput.  In the photographs, the joins look a bit ragged, but when you run your finger over them it feels like a single unblemished sheet of plastic..  













I will cut a section from the firewall to fit the lowered cowl.  The height reduction will be a bit more than the height of the sections removed from the cowl because, unlike Pocher intended, the firewall will be mounted flush with the leading edge of the cowl, like the prototypes.  The internal dimensions of the cowl are smaller at the leading edge.


I removed the ridge at the top and sides of the firewall as it seems to be present only on the Pocher models.  The pencil marks indicate the approximate size and location of the section I will remove.


The strengthening ridges on the firewall are incorrect.  On the prototype firewalls, the stampings protrude inward rather than outward. Fixing this would require a milling machine. 






I neglected to photograph the firewall before I removed the top ridge.  Here is the ridge in a photograph taken from Paul Koo's CD.





The next steps will be to separate the cowl from the bottom door jambs and the rear body and to lower the jambs and rear body 4mm over the frame.   This will put the door jambs at the correct height relative to the top of the frame and the leading edge of the rear deck at the proper height relative to the height of the cowl.  Note that the cowl was lowered 7.5mm and that the rear deck will be lowered just 4mm.  This should make their relative heights more consistent with the prototypes without the need to increase the height of the front portion of the rear deck with styrene sheet and Milliput.  The procedure I used for the first body dictated that the front and rear of the body were initially lowered equally..


After these steps have been accomplished, the major tasks of shortening and radically re-contouring the rear of the body will begin.

Edited by Endeavor
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Using the flush cutting saw, the cowl was separated from the bottom door jambs and rear body.


 A 4mm section was marked off under each door.





One of the two saw cuts-in- process.





One of the 4mm panels is removed.





The two sections of the body are placed into position and the wheels are mounted so that all of the measurements can be checked once again.  Some minor adjustments were made to fit the rear body to the frame, including a small section removed above the forward rear spring mounting bracket.


The leading edge of the rear deck is 2mm too high relative both to the ground and to the  cowl.












Edited by Endeavor
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Man I'm glad I stayed up 'late' and saw this!


Speaking of 'saw', that saw is worth it's weight in gold. And you use it like a surgeon -!

Spectacular work at this stage. :worthy:

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David, if it's really important to you to have the firewall stampings made correctly I have a thought. But it's at the 'insanity level' of detail work and I don't want to waste your bandwidth. No mill needed...


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