What is poor man’s fibreglass?

In today’s blog post, we will answer the following question: What is a poor man’s fibreglass? We will explain how you can make poor man’s fibreglass, what to use it for, and some alternatives to it. 

What is poor man’s fibreglass?

Poor man’s fibreglass (PMF) is the process of combining three elements to obtain cheaper, durable and paintable homemade fibreglass for your trailer. The three elements are:

  • An adhesive (ex. Titebond 2) mixed with water;
  • Gripper (primer for paint);
  • Canvas (or bedsheets). 

How to apply poor man’s fibreglass?

Poof man’s fibreglass is popular precisely because it is easy to apply to your trailer. Here are all the materials and tools you will need for the entire process:

  • A paint roller
  • Detail brush
  • Fabric: old sheets are the easiest to find
  • Exterior paint 
  • Newspaper/plastic bags to avoid stains
  • Gloves
  • Pair of scissors
  • Sandpaper or sander
  • Mask to prevent breathing the colour.
  1. Prepare the surface: Sand the parts that will be in contact with the fabric well with sandpaper. We want a smooth and even surface: we will round corners and fill gaps and cracks with glue or putty. At this point we seal the wood with a mixture of oil-based polyurethane paint diluted with 25% oil-based solvent. Once dry, sand with a coarse grain to give it grip.

In the case of boats or wood surfaces, giving this mixture delays the water reaching the wood and rotting it.

  1. Apply the canvas: It is important to cover the surface well with the fabric. We cover with the cloth making sure to exceed the edges with a few extra inches so that the corners of the fabric overlap (ensures waterproofing) and cut the piece.
  1. Paint: We paint the piece of fabric that we have cut on one side. Then we paint the wooden structure. Then we put the amount of fabric, and we continue painting from the centre outwards. Keep painting until the material is soaked in paint and shiny from wet paint. 

Let it dry for 10 min and soak the fabric again with the roller. We repeat until, after ten minutes, the paint continues to have that shiny appearance: it is proof that it does not need more colour.

Once this first coat is dry, we can paint with the colour we want for the finish. Keep in mind that the paint will take a long time to dry!

Affordable poor man’s fibreglass alternatives

PMF is made by weaving fibreglass strands together and reinforcing the frame of small boats and trailers, giving it light strength. Because it is woven, PMF is very flexible, making application easy. 

However, the environmental community frowned upon poor man’s fibreglass because it requires harmful chemical treatment for commercial use. Alternatives, or products made from these alternatives, are altogether a bit more expensive than fibreglass but cheap in terms of their impact on the environment:

  • Bamboo: Companies, like Greenlight Surfboard Source, manufacture a natural bamboo glassing cloth that shares several of the characteristics of PMF, except, of course, for its harmful effects on the environment. 

Glassing bamboo fabric is made from one of the most durable and versatile renewable resources on the planet. It is flexible and robust, which is ideal for laminating surfboards and other boats. Bamboo glazing cloth is about $ 6 per foot.

  • Hemp: The hemp plant has gained a negative reputation for its association with cannabis, but it is genuinely a hardy plant that does not deplete the soil and has a variety of uses. 

The hemp plant helps remove carbon dioxide from the environment as it grows, which is more than can be said for fibreglass, which relies on toxic petrochemicals for treatment and processing. 

Hemp cloth is an eco-friendly alternative to fibreglass that is also inexpensive to make and use. 6.5-ounce hemp fabric from a retail outlet costs about $ 30 per yard; heavier materials cost more and bulk orders cost less.

  • Natural grass: Like hemp, natural drying cloth can be woven from grass, a suitable alternative to PMF, which is also available in abundance. Natural grass can be sourced locally from saltwater habitats, so the resulting fibre is tough and resistant to wear and tear.

Look for manufacturers that use natural grass fibres for eco-friendly and related surfboard products instead of standard fibreglass. Natural grasscloths cost similar to bamboo cloths at around $ 6 per foot.

  • Basalt: Basalt fibre makes a mineral-based cloth composed of plagioclase, olivine, and pyroxene. Basalt fibre is even more durable than fibreglass and carbon fibre, also similar although it is much cheaper to manufacture than the latter. 

Unlike fibreglass, no chemicals or materials must be added to basalt to make basalt fibre, which is sourced from carefully selected quarries, washed and cast. 

Is aluminium a better choice than poor man’s fibreglass?

Of course, if there is a choice, we recommend always using aluminum over fibreglass for your boat or trailer. We remind you that while it is durable, poor man’s fibreglass is not exactly the best material for your trailer. 

The exterior coating of the aluminium trailer is more resistant to cracks than homemade fibreglass. This is certainly another big plus if you plan to hit the road with your trailer. Seasonal campers, however, will see very little difference to park trailers or stationary trailers.

In the event of water infiltration, it is generally less expensive to repair the aluminium trailer, because the sheet metal does not rot (but be careful, the wooden structure inside the trailer rots during water infiltration).

As for them, fibreglass trailers often have an aluminium structure (wall studs) that does not rot. But when water infiltrates, fibreglass is much more expensive to repair.

Obviously, water infiltration can be avoided with regular maintenance of your trailer to ensure its durability.

On that note, aluminium siding panels are easy to replace, but replacing smooth or polished aluminium generally requires the expertise of an automotive technician. Aluminium cladding is lighter than fibreglass, so the caravans can be transported by vehicles with a lighter towing capacity. 

The lightweight aluminium provides the option of purchasing a larger caravan than one with fibreglass cladding which increases the weight. Aluminium siding is generally less expensive than fibreglass and has better breathability, reducing condensation and mould growth inside the RV. Painted aluminium siding typically lasts longer than fibreglass laminated siding.

The bottom line

As you have seen in this article, there are several advantages of using poor man’s fibreglass. It is indeed a simple and practical way of coating your trailer. And perhaps the biggest advantage of them all is that it is easy to paint over!

Do you have any questions, comments or perhaps suggestions on using PMF? Let us know!

FAQ on What is poor man’s fibreglass?

What is poor man’s fibreglass?

Poor man’s fibreglass (PMF) is the process of combining three elements to obtain cheaper, durable and paintable homemade fibreglass for your trailer

How long do fibreglass trailers last?

Fibreglass trailers last around 10  years, however, the lifespan of a caravan will largely depend on how well you maintain it!

Which is better: fibreglass or aluminium RV?

When deciding which is better, fibreglass or aluminium RV, we have to discuss the following criteria:

  • Durability;
  • Convenience;
  • And water leaks;

What is a good substitute for fibreglass?

The following materials are a good substitute for fibreglass:

  • Hemp;
  • Bamboo;
  • Wool;
  • Soy-based foam;
  • Natural grass, etc.

How long will the poor man’s fibreglass last?

Poor man’s fibreglass is long-lasting and very resistant material. It can last up to 40 years, but it will need contact maintenance and perhaps a repaint job every five to ten years. 

How do you make homemade fibreglass?

You can make homemade fibreglass by combining fabric (canvas) with a paint primer and a good adhesive (sometimes diluted with water). Prepare the surface and then apply the adhesive and the canvas. Coat the fabric with a resistant primer then paint over with the colour of your choice!


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