Jul 31
Fiberglass Finishing
posted by: Steve Jones in Uncategorized on 07 31st, 2017 | | No Comments »

When I first started working with fiberglass, I found it a fascinating yet frustrating material. While I enjoyed the fact that it was water proof and could be formed into any shape, I was often frustrated by my attempts to finish it in a way that would make my final product look presentable. Over the years I have come to the realization that a nice fiberglass finish requires a little preparation and a little improvising.

Obtaining a nice smooth finish can be obtained on a consistent basis when using a mold to produce your parts. Even so, thought and preparation are still necessary. A nice thick gelcoat layer that is covered with a layer of veil that is then covered with a layer of chopped mat will create an end product with a nice finish and no pattern transfer to the final product. The gelcoat layer should be thick enough to allow light sanding without getting into the mat.

When repairing a broken piece of fiberglass, getting a smooth finish takes a little more work. On painted surfaces, I like to remove the paint around the damaged area with sandpaper. Depending on the size of the damaged area, I like to remove enough paint around the damaged area to give me a couple inches of working room. I will then tape over the finished side of the damaged area and apply my repair to the backside of the repair.

Once the resin has cured, I remove the tape and access the exterior of my repair. If the repair is flush or depressed, I will smooth over the surface with either bondo, finishing putty or a thick mixture of resin and cabosil. Once this has cured, I will sand it smooth, primer it, inspect it and go from there. If there are defects in the surface, I will refill them with the medium that I find appropriate and repeat the sanding, inspecting and primering that I had done before. This process continues until the finish is right.

You should not be afraid to sand fiberglass. If you happen to sand it to the point that you expose glass fibers, clip the long ones off and brush more catalyzed resin on. Let the resin cure and re-sand. You may have to repeat this process several times to get your repair right. If your sanding continues to expose fibers, you may want to cut the surface down an 1/8 of an inch or so and fill over the surface with either gelcoat, resin mixed with cabosil or even bondo. Once this has cured you will have plenty of room to shape and sand without exposing fibers.

The bottom line is that many people feel as though the final outer surface of a fiberglass repair must be fiberglass. This is nice if possible, but there is nothing wrong with smoothing over the outer skin of a fiberglass repair with gelcoat, bondo, resin mixed with cabosil or body putty.

Fiberglass Shooting Star Body (Speed Racer) For RC Car

Happy Glassing


Steve

www.fiberglassmoldmanual.com

Jul 30
Fiberglass Boat Build Continued…
posted by: Steve Jones in Fiberglass Boat on 07 30th, 2017 | | No Comments »

In my last post I addressed an issue that I was having with the plug that I am building for this fiberglass project. At some point after the sponsons were covered with mat and resin I realized that they were simply too big in diameter. To correct this problem I cut the fiberglass covering off with a Dremel tool and then used a chisel to scrape the building surface clean of foam. After rebuilding the sponsons with foam and fiberglass I begin to follow the … Read the rest of this entry »

Jul 28

Now, I move forward with creating buck stations. A buck station is a guide that ensures that your plug is going to resemble what you want it to in the end. For this project I use the same 1/8 inch mahogany that I used for the initial profile pieces. My strategy for placement of buck stations is simple, I put one anywhere that I am concerned about maintaining the correct lines of my project. Usually I am of the opinion that more stations are better. Read the rest of this entry »

Jul 26
Fiberglass Model Boat Build Moves Ahead!
posted by: Steve Jones in Fiberglass Boat on 07 26th, 2017 | | No Comments »

Getting back to building the base for the assembly of my hull, in the previous post I had just assembled the base and am now preparing to attach the piece of cut mahogany that will define the periphery of my hull.

[caption id=”attachment_83″ align=”aligncenter” width=”300″ caption=”The Building Base will define the shape Read the rest of this entry »

Jul 25
Fiberglassing for Profit: Part 1
posted by: Steve Jones in Uncategorized on 07 25th, 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. 

 

                          

 

 

Jul 23
Fiberglass Boat Repair 11 Meter RHIB Model
posted by: Steve Jones in Fiberglass Boat on 07 23rd, 2017 | | No Comments »

Once I realized that my sponsons were too large (had I been paying better attention I would have figured this out prior to covering them with fiberglass!) my attention turned to what to do about them. Read the rest of this entry »

Jul 22
Fiberglass RC Boat Project: Post #1
posted by: Steve Jones in Uncategorized on 07 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

Jul 20
Joining Fiberglass Halves
posted by: Steve Jones in Uncategorized on 07 20th, 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

Jul 19

With the keel and the hull sides attached, I can think about filling the hull with foam and carving out the bottom of the hull. As I study the hull bottom as it sits, I notice that the hull sides have some waves in them. Since it is much easier to fix this now, I go ahead and glue then clamp some thin pine strips along the inside of the hull sides about ½ inch below the upper edge. This strip will also help me with the construction of the hull bottom. Once these extra hull pieces are secure, I measure and cut Read the rest of this entry »

Jul 17
Fiberglass Fender Build Part 5
posted by: Steve Jones in Uncategorized on 07 17th, 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.

 

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