Dec 11
Fiberglass and Foam Plug Building
posted by: Steve Jones in Uncategorized on 12 11th, 2017 | | 1 Comment »

Its funny how we do things that we think are not only the right way but the only way only to find out later that there are better ways. Years ago, when I first discovered the use of dry foam as a medium for plug construction, I thought that I had found the perfect plug building material. I easily carved out complex structures in a fraction of the time that it used to take when I used plaster and wood.

Then my bubble burst. I finished carving the foam for my new plug, covered it with resin and sea glass from the hobby store and let it cure. To my surprise, when I was applying bondo and glazing putty to level the surface of my plug, the plastic putty knife that I used easily went through the surface of my plug. It was then that I realized that the outer skin of this plug was too weak and needed re-enforcement. I fixed this problem by removing the thin layer of glass that I used to cover the foam and applying a 1/8 inch layer of bondo over the entire surface of my now less than pretty plug. Since this episode, I have always used foam in my plug construction but I always took that extra step with shaving down the foam and covering it with a layer of bondo before I start the final finish.

Recently, I began to evaluate my plug building procedures. While my tried and true method described above never failed me, I wanted to try something new. I recently was building a plug that I wanted to move quickly with. After carving the foam, I went ahead and decided to cover it as it was with 1 ½ ounce chopped mat and resin. I remembered when I had my bad experience with this method I had used very light material from my hobby shop. The 1 ½ ounce mat worked perfectly. It provided a very solid surface to work with without adding excessive size to the plug that I had carved from the foam.

I basically did two things differently with the foam. The first thing that I did was thoroughly saturate the surface with resin. The second thing that I did was use a much heavier chopped mat to cover the plug.

I always read and research fiberglassing techniques. I had not really researched or evaluated my plug construction techniques for years. This “new to me method” saved me a TON of time and materials (bondo). I don’t believe that this way of plug building affected the quality of my final product at all.

I would recommend trying this method for your next project.

Happy Glassing


Steve

www.fiberglassmoldmanual.com

Dec 6
Fiberglassing for Profit: Part 1
posted by: Steve Jones in Uncategorized on 12 6th, 2017 | | No Comments »

I have made many things out of fiberglass over the years.  Typically, my projects involve building a plug, making a mold from that plug and finally using that mold to make pieces. 

 

One project that I have wanted to do for a while was inspired by a ceiling fan that I first saw years ago.  I am sure that you have seen the fans that look like the nose of a WW II fighter plane.  From the moment that I saw that fan, I thought that it would be cool to have a helicopter body that would hang from the underside of the ceiling fan making the fan blades look like rotor blades.  Of course the helicopter would have to be a classic – I chose the UH-1 from the Vietnam era.

 

Thus the project begins.  The first thing I like to do when I am building something like this is to go to the hobby store and pick up a model of the helicopter that I want to build.  I use this model as a three dimensional reference.  While 3D references are not always available, I do like to use them when possible.  For this project, I selected a 1/35 scale UH-1.  Using this model, I can get a good idea of the size that the fuselage has to be relative to the diameter of the fan blades in order to maintain a scale appearance. 

 

I begin to build the fuselage of the model and to analyze the proportions, angles and curves of the copter.  

 

At this point, I can begin to produce profile drawings of the copter.  I definitely need to start with a view from the top and a view from the side. 

Some of this is accomplished through artistic ability and some of it is cheating.  The model that I bought had these views in the painting instructions.  Based on the diameter of the fan blades, I figured that the fuselage should be about 40 inches from nose to tail.  I simply used my copier to blow these views up to the size that I need.  Then I drew in some details that were lost in the enlarging process. 

 

                          

 

 

Dec 5
Fiberglass Copter Build Part 8
posted by: Steve Jones in Uncategorized on 12 5th, 2017 | | No Comments »

I begin by applying black tooling gelcoat with a dump gun at about 80 psi. I make sure to keep the gun close to my work because gelcoat makes a huge mess if it gets on something other than your project. I lay down a nice thick layer of gelcoat making sure to get good coverage around the base where the plug meets the board.

Once the plug is covered with gelcoat, I let it cure to a tack. I did this project on a nice hot San Diego day so it cured to a tack in about 45 minutes.

At this step I used a different approach than I am used to. I came into possession of a large roll of veil that I decided to use in the corners and angles of the mold. In the past I have always used a combination of cabosil and resin. I found the veil easy to work with, especially when pushing it into corners with a chip brush. With the veil in place, I proceed to build the mold with three layers of 1 ½ ounce chopped mat.

I begin applying the chopped mat by brushing a nice thick layer of catalyzed resin over the area of the plug that I am working on. Then I place a piece of mat that has been pulled off of my roll and lay it on the plug. I like to keep the pieces fairly small on a project like this, no larger than 6 inches square. Pulling the mat apart will leave many loose fibers that will help the strength of my final product once it has cured. When applying the mat, I like to overlap my pieces by about 20% and build a nice flange around the base of the plug.

Happy Glassing


Steve

www.fiberglassmoldmanual.com

Nov 28
Fiberglass Fender Build Part 5
posted by: Steve Jones in Uncategorized on 11 28th, 2017 | | No Comments »

After the resin cures, I like to let the new mold sit untouched on the plug for a few days.  Letting the mold sit for a few days prior to de-molding helps prevent warping of the mold.  In this case, my plug is of a long, thin fender and has a much greater chance of undergoing a noticeable warp then some of my other projects so I am more careful at this stage then usual. 

 

De-molding the fender becomes an easy task.  The PVA and wax layers were not breached and as soon as I began to pull one corner of the fender plug loose the entire mold separated from the plug.  Just as planned – so far.

 

The next step in a project like this is to clean up the new mold of any defects or sharp edges around the flange areas.  I begin by using a rag and water to remove the PVA from the inside of the mold.  The result of my cleaning reveals a perfect molding surface.  Had I found any defects, I would have filled them with bondo, sanded them smooth and then thoroughly waxed over them before molding any parts.

 

In order to make my first parts with this mold I begin by applying several (four) coats of mold release wax to my mold’s surface.  When the wax has dried and has been polished to a smooth shiny finish, I apply two coats of PVA with a foam brush.  On larger projects I will use my air gun but this project didn’t warrant that much hassle.  In this case, I applied a light PVA coat, allowed it to fully dry, then applied a second coat for extra protection.  With both the PVA and the wax applications I made sure to cover any areas of my mold, including the flanges that were formed over the parting plane.  This will insure that my parts don’t get stuck on the mold.

 

Nov 24

Continuing with the helicopter build …

 

At this point, I can begin to produce profile drawings of the copter.  I definitely need to start with a view from the top and a view from the side.

Some of this is accomplished through artistic ability and some of it is what I consider cheating.  The model that I bought had these views in the painting instructions.  Based on the diameter of the fan blades, I figured that the fuselage should be about 40 inches from nose to tail.  I simply used my copier to blow these views up to the size that I need.  Then I drew in some details that were lost in the enlarging process.                            

 

The next step for me was to trace these profiles onto a base that I can use to build a plug.  I like to use 1/8 inch mahogany door skin for this.  I like mahogany because I can buy it at home depot for cheap and one sheet is more than enough material for a project like this. 

 

Next, I want to decide along which line to epoxy the primary horizontal shape to the vertical shape.  Having access to my plastic model makes this decision easy.  Angle aluminum stock helps me align the mahogany pieces with each other.  I use the angle aluminum to clamp the pieces to each other which assures reasonably accurate alignment of the parts.

                                                                      

In addition to angle aluminum making alignment of not so straight pieces easier, it also gives a pretty good 90 degree alignment of one piece to the other. 

 

At this point I need to make a statement concerning scale.  I am no artist, I know from the outset of a project like this that when I am done, anyone who knows anything about helicopters is going to look at this and say “Hey, that’s a Huey UH-1”.  That is good enough for me.  You can put as much talent and time as you wish into a project.  This is your prerogative.  I like to get a project’s detail to the point where I am satisfied.  I think that I am usually satisfied with my projects bearing a close resemblance to the vision that I started with.  That being said, nothing that I ever build will ever be completely scale (unless I happen to trip over a bucket of talent and patience).  That is all I have to say about that.

 

More Soon

 

Steve

 

Nov 22
Fiberglass RC Boat Project: Post #1
posted by: Steve Jones in Uncategorized on 11 22nd, 2017 | | No Comments »
A friend of mine who spent an enlistment period in the Navy as a SWCC asked me if I could build a model of the 11 meter RHIB that he became fond of while in the service. I have always enjoyed building model boats so this was an easy decision for me. Not only did I want to build it for him because I like to do those things for people that I consider friends, but this will be a unique project for me. I have never even considered building a boat with an open deck. The 11 meter RHIB has an open deck with exposed seats, control console, and armament – lots of potential detail. Lucky for me I can consult with my friend regarding the details of this project.

For my friends purpose, this is going to be a display only model. I will definitely make mine radio controlled. The differences in the two models should be minimal with the RC version simply allowing for easier access to the underside of the deck.

The full scale 11 meter RHIB is approximately 36 feet long. The first this that needs to happen is we need to decide on a size. My buddies wife would be happy if it were no longer than a foot from stem to stern. I think that making it 1/6 scale to fit GI Joe would be the way to go. Obviously we are pretty far apart on this so we decided on 1/10 scale making it about 43 inches long. This sized boat will allow me to buy some off the shelf detail pieces such as guns, ammo boxes and maybe even the 50 caliber machine guns (hopefully, I would hate to have to make these!)

Scale is important with a project like this. To make sure that I get as close as possible, I scour the internet looking for photographs and drawings of the 11 meter. I was able to get my hands on a digital owners manual which was of great help as well. The first thing that I did with my photographs and drawings was to use my copier to blow up a drawing of the 11 meter from the top and from the side. My copier has a function that lets me resize a picture up to 200% with each pass through the machine. I did the math and ended up with side and top perspective drawings that give a length of exactly 43 inches long and 16.5 inches wide.

This series of blog posts will be done in real time and will follow my project as I make progress. Stay tuned!! I will post pictures as I progress.

Happy Glassing


Steve

The 11 Meter RHIB

www.fiberglassmoldmanual.com

Nov 18
Joining Fiberglass Halves
posted by: Steve Jones in Uncategorized on 11 18th, 2017 | | No Comments »

There are several ways to join fiberglass halves. Fuselages, boat hulls and car bodies usually require joining of at least two pieces in order for the project to reach a point of completion.

With some applications, a sleeve can be built into the plug with will allow the second part to slip into which will result in a nice joint that can be epoxied together. An application that comes to mind in this circumstance would be the deck of a model boat to the hull. This technique needs to be planned well in advance since it requires integration into your plug. This technique also is only applicable to those projects that won’t be visually hampered by a visible seem or joint on the final product.

Most of the time, in order to obtain a clean joint that can be filled, sanded and finished in a way that produces no visible joint on the final product, you will need access to the inside of the joined pieces in order to produce a clean union. The best way to do this is to align the halves and use masking tape to hold the pieces together. I like to use thin strips of resin saturated fiberglass mat that I can lay across the inside of the seem. Depending on the strength of the bond that my project requires, I like to have about ½ inch of mat overlapping each side of the seem. Once this cures, your joint is complete. The only thing left to do at this point is finish the exterior.

Another method that I really like for joining fiberglass halves that don’t have to be water tight or incredibly strong is by using what I like to call “chemical applesauce”. “Chemical Applesauce” is a mixture of resin and cabosil that has been catalyzed with MEKP that has the consistency of applesauce. I use this mixture by taping the entire outer surface of the seem, making sure that the pieces have proper alignment. I then use a gloved finger to apply this mixture to the seem line from the inside. I use my finger to push and work the mixture into the joint. This makes an excellent filler as well. Once the mixture has cured, I can remove the masking tape and I am left with a strong, clean joint that requires only minimal sanding and finishing.

These are some of my favorite ways to join two halves of a fiberglass project. I do have a challenging project on the table now that will require special consideration when joining. I will keep you posted on my progress.

Fiberglass AH-1G Cobra

Fiberglass AH-1G Cobra

Happy Glassing


Steve

www.fiberglassmoldmanual.com

Nov 15
Fiberglass Fenders Part Two
posted by: Steve Jones in Uncategorized on 11 15th, 2017 | | No Comments »

Now that the foundation for my plug is laid, I can start building a fender. At this point I will just take a moment to regress.

When I was younger, I am sure that this plug would have been built from a much more difficult process than what I have outlined. I am not sure how I would have done this but it wouldn’t have been easy – I probably would have used a template of the rim, done complicated measurements of the total tire diameter and so forth. Building plugs for projects like this are much easier and more likely to provide a nice product if you can use the base object as the foundation for your plug. In this case, I used the actual rim itself. In one of my manuals, I actually used the hood of my jeep as the foundation for building a plug for the hood scoop. This method of plug building takes much of the guess work out of the building process.

Getting back to the plug, I begin building the plug by laying a layer of 1 ½ ounce mat and resin over the foam. Once this cures, I follow with a plastic spreader and bondo to smooth out the surface of the fender. Once the bondo is cured, I smooth out the surface with my electric sander with a course (100 grit) sandpaper to smooth it out. Like with any plug build, I go through many bondo applications followed by sanding to smooth out the surface.

As with many plugs, just about the time that I get this thing smoothed out I see a problem with it. From a side view, it appears as though the center section of the fender, when viewed from the side, isn’t as thick as the ends of the fender. In order to check this, I drilled a hole in the end of a 1/8 inch, inch wide by 36 inch long piece of aluminum stock. The hole is just large enough to slip onto the hub of my rim. I then clamp an L bracket onto the stock aluminum and slid it down until it makes contact with the fender at what I perceive to be the highest point. As I sweep the L bracket around the top of the fender from one end to the other it becomes obvious that not only is my center section low, but I have many uneven points along the surface of the plug.

Fixing these uneven points is pretty easy. I now have a way to measure the outer diameter of the fender and I can use this tool to obtain consistency in the outer diameter.

To smooth out the surface of my fender, I lay a bead of bondo in the center along the length of the plug. While the bondo is still able to be spread, I drag the L bracket which is still attached to the hub through the aluminum stock along the surface of the plug at a level that represents the highest point of the plug. The L bracket levels the surface of the plug creating consistent thickness of the plug.

After this application of bondo cures, I can begin spreading bondo over the surface again to smooth it out. This time I am careful to use the newly laid central ridge of bondo as a guide.

Happy Glassing


Steve

www.fiberglassmoldmanual.com



Nov 13
Fiberglass Fenders
posted by: Steve Jones in Uncategorized on 11 13th, 2017 | | No Comments »

My most recent fiberglass project is a set of fenders for my beach cruiser. I know that there are already fenders available on the market, but I really didn’t care for them. In addition, I do enjoy building my own things when I can and it just so happened that this would be one of those projects.

To start with a project like this, I first needed to decide how I would get the shape and size of a fender that I was looking for. I want to have a fender with a round contour that would provide better coverage of the tire than what store bought fenders provide.

Initially I considered obtaining the right shape for the fenders by covering an inflated tire on the rim with foam weather stripping and then using that as the foundation on which to build a fender. The more I thought about this the more problems I was imagining.

Then one day I was walking by the 99 cent store and I saw those round foam pool toys that the kids use, I think they are called noodles. I knew right away that I was 99 cents away from the perfect base on which to build a plug for my fenders.

Once I got that foam roll home I pulled a wheel off my bike, removed the tire and proceeded to tape that foam roll to my rim. It fit the channel perfectly, and was the right height and width. I wanted my fender to cover about one half of the diameter of my tires so I used enough of the foam to accomplish this.

With the foam roll secured to the rim, I decided to cover the foam with a layer of masking tape. I did this to protect the rim and because I wasn’t entirely sure what the fiberglass resin would do to the foam, or if it would release cleanly from the foam.

At this point it is time to think about applying the fiberglass resin and mat. I began by building a simple cardboard stand to hold the rim steady while the materials are applied. Once I was happy with the stand I covered the entire rim and tape covered foam with PVA release agent.

Now I am ready to build a fender plug.

Happy Glassing


Steve

www.fiberglassmoldmanual.com



Nov 9
Fiberglass Fender Build Part 4
posted by: Steve Jones in Uncategorized on 11 9th, 2017 | | No Comments »

In order to mount this plug to a parting plane, I am going to need a flexible piece of material, something that will easily follow the curve of my fender plug without causing distortion. What I ended up with is a six-inch wide piece of mahogany door skin that will act as the parting plane that will be mounted to a one inch thick, six inch wide by 36 inch long piece of MDF.

To mount the fender plug to the door skin, I used some bondo to stick wooden blocks to the inside of the fender plug and then I screwed the mahogany to the blocks. I then used my hot glue gun to attach the ends of my newly mounted plug and parting plane to the MDF. Just for visual reference, what I ended up with was similar looking to the Dunlop walk-over bridges that you see crossing over the track at automotive races.

With the plug mounted, I am ready to start the molding process. As with all plug molds, I begin by filling any and all gaps that exist between the plug and the parting plane with clay. In this case, I had no gaps so I went straight for the mold release wax. Since my parting plane is a very porous mahogany, I used 5 full coats of wax to ensure that the chances of my plug sticking to the final mold would be minimal. I allow the wax to completely dry and then apply two coats of PVA mold release and allow it to dry.

This plug is now ready for molding. Anyone who has read any of my prior blog projects knows the process that I am about to explain. I begin by mixing enough black tooling gelcoat to brush a nice thick coat over the surface of my plug and parting plane. Once this cures to a tack, I apply three layers of 1 ½ ounce fiberglass matt and fiberglass resin.

When applying the fiberglass mat and resin, I am always careful to make sure that the material has no air bubbles trapped inside. This is especially important with the corners. In this case the critical area is where the plug meets the parting plane. Remember, hurrying through this portion of the mold build will result in defects in your final product. The more defects that you have – the more repairs you will have to make to your parts.

Happy Glassing


Steve

www.fiberglassmoldmanual.com



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