Fiberglass is a tough and sturdy material often used in the construction industry. It is made up of a fiberglass cloth woven with glass fibers and then coated with resin. The resin can be applied by dipping the material into it or brushing it on and then drying it.
The question of whether you can lay Fiberglass over plastic bumpers has an easy answer below. Let’s check it out!
Contents
Will fiberglass stick to plastic bumpers?
Fiberglass doesn’t stick very well to plastic. Usually, people drill holes in a panel to adhere Fiberglass to it. You are better off getting a small piece of ABS plastic.
The best thing to use is a two-part epoxy for plastics—drill holes on both ends of the crack, Dremel out the jagged edges of the damage.
When that epoxy dries, it will reinforce the area and bond to the plastic.
West Systems makes a product for plastic boat repair called “G-Flex” for repairing plastic kayaks, canoes, etc.
They can glue a scrap bumper behind it. It usually keeps pieces like that for this purpose.
Can Fiberglass cover ABS plastic?
If you use too many chemicals, there’s a possibility of warping the hull. I once used an ABS hull as a plug for some deep V-shaped hulls. It wasn’t easy because it twisted and ripped after one or two pulls.
To be sure, fill your hull with clay before you place the framing and bulkheads. Then complete a plaster mold of the frame and make new ABS sheets. I tried this recently, and it saved me a lot of time.
Theoretically, you could put the frames into the hull rough up the exterior with coarse sandpaper and glass on the outside. If you wanted to do the inside of the hull and save the exterior finish, he would have to resize the frames.
Most kits will not need much in the way of additional reinforcement because they are well designed. Polyester resin, however, melts ABS, so use epoxy resin.
If you want to fiberglass an ABS hull, we’ll also recommend that you don’t use polyester resin. Yes, it is possible to apply Fiberglass to a foam-filled ABS sheet, but you should be aware of some issues.
If you need a thicker and stronger hull, the best option is to make a custom mold. Applying Fiberglass to your original hull will give it a thick and unsightly exterior.
You can make a mold of this by applying Fiberglass if you first cover it with a good, thick layer of PVA. Make sure you use a PVA barrier coat before pouring the resin because if it melts or touches the pain, it’ll stick and ruin the mold.
An ABS hull is perfect for a slow-moving boat because it doesn’t need to be reinforced with Fiberglass. It lasts forever if the ship is not dropped or stressed.
Fiberglassing over Urethane?
Urethane is pretty darn flexible stuff. Most auto body people consider Fiberglass to be a semi-rigid material. Are you combining these materials? Not such a good idea.
If you want to achieve a one-piece effect, I think it may be too complicated for you. For something more simple, here’s how I would do it instead.
The best thing you can do to continue your learning process is to take advantage of this forum and discover links to the material. There are also links for free articles for tutorials on the subject.
What should you use to repair the bumper?
You can use a fiberglass Bondo to reinforce a cracked bumper. The repair was undetectable from the outside.
Many people will use Fiberglass to fix bumpers. It is wrong because they are not polyester but epoxy.
You could also use wax paper. Wax paper is a practical means of fixing holes in a car by smoothing a paste mix over it whether you choose Bondo, resin thickener, etc.
Multiple layers of 4 oz glass are better than just one layer of heavier glass. You should scale infographics layers in size, so the edges are not stacked on top of each other.
If the surface gets sticky, then this is because you used too much resin. A way to fix this problem is to put wax paper on top of it and sand it with a rotating motion. Most plastics share the same texture, but polyethylene feels different to the touch. It never sticks to the resin.
If you use polymer or plastic garbage bags to vacuum bags, be sure that the resin is appropriate – some only work for single-ply, others are cross-linked and can withstand moisture. To mix things up a little, try staggering the glass panels as well as brushing on the sanding resin.
Cracks in plastic bumpers fixing?
Several months ago, I noticed a crack on the front bumper of my 11′ Lancer SE. The guys at the body shop beside me told me it was useless to do anything.
If a new 11′ Lancer bumper is out of your budget, you could fix it and make it pretty while you save for one. If you mix the resin right and prep the bar well, you might use Fiberglass.
A proper plastic welder will be able to weld the crack shut. But that crack you have is nothing. I would personally repair that with 406 or polyurethane glue like sikaflex. The 406 will be least likely to crack through.
File it than sand. Spray a few coats of paint. Over it rough and drive around for a month.
Superglue+talcum powder makes a great strong ‘bog.’ The staff is amazing. It’s like super glue but stronger and sets twice as fast. You can glue steel together.
What should you use other than Fiberglass?
Fiber reinforcement on the cutting wheel will prevent any cracks from showing up in the future. Make a shallow ‘V’ shape and apply drywall compound to cover it up to expose the damage. It allows you to fill any damage with new material and put some more on top of it.
Be sure to sand the area smooth, then do it again with a bit of water and a block of wet & dry. First, paint a layer of high-build primer to help seal the surface, so it doesn’t crack. Then sand with a fine-grit and do a final coat. There won’t be any cracks, and the finish will be strong.
Many people make a false assumption that Fiberglass is metal and cut into it with a Dremel. 3M makes several products that can repair various types of bumpers.
JB Weld is a good epoxy with a long working time and excellent strength. It may be a bit heavy for a model, but use the Saran Wrap/or other plastic film technique to squeegee out the excess resin.
Use Isopropyl Alcohol to clean up. Use ethyl alcohol for drinking.
