need a fiberglass guide/advice
- Thread starter Roadblock
- Start date
Michael Yount
Mustang Master
alanw6
Member
I can help you out I think. Basic fg work is not too complicated, requiring more patience than anything. It's definitely more art than science, but a familiarity with the materials is helpful and comes with some pratice.
What kind of project are you considering? I can assist you in material selection (both ideal and/or readily available) and some tips/tricks.
Let me know,
Alan
What kind of project are you considering? I can assist you in material selection (both ideal and/or readily available) and some tips/tricks.
Let me know,
Alan
alanw6
Member
Roadblock said:
Sounds like a pretty interesting project. If it is your first attempt with fiberglass whatsoever, be careful. That will be a large part, and will require a lot of time to do right. I've seen many ambitious fg projects get scrapped because they ultimately took too much time/effort to finish. My recommendation would be to "cut your teeth" on a smaller project, thereby learning the nature of the materials and getting a feel for the process.
You will definitely get better with fg each time you use it, I know that is the case with me. Search under my username in the 5.0 talk section for a gauge cage I just did in fg. Finished pics will be up in a few days. Even as small as this part is, it has taken probably 12 hours to acheive the pictured finish.
If you have any specific questions on your mind, let me know. I can try to answer them, or point you to a resource with good information.
Michael Yount
Mustang Master
I'll wade in here too Alan -- my car has relatively simple aluminum extrusions that form the base of the bumpers. These extrusions have large rubber pads on them - and I'd like to both eliminate the pads, as well as reduce the weight of the bumpers (these extrusions are very stout and despite being aluminum are quite heavy). The problem is that the pads are bolted on from the back side of the extrusions, and simply removing them will leave the bumper filled with holes.
So I thought I might make a mold from the existing extrusion from which I can then pull a replica bumper out of fiberglass.
I'm curious about what types of glas to use (strips, weaves, fibers, etc.) and what resin. Also, I'm not certain a one piece mold is gonna do - the sides of the bumpers (wrap around) have a slight curve to them that I think will make it difficult to extract the fiberglass piece without stressing/breaking it. So I may need a two piece that I can unbolt/disconnect in the middle and slide the halves off of the finished piece. Kind of hard to describe without pics. Also, would love to have your thoughts about mold materials (plaster vs. fiberglass) and release agents.
So I thought I might make a mold from the existing extrusion from which I can then pull a replica bumper out of fiberglass.
I'm curious about what types of glas to use (strips, weaves, fibers, etc.) and what resin. Also, I'm not certain a one piece mold is gonna do - the sides of the bumpers (wrap around) have a slight curve to them that I think will make it difficult to extract the fiberglass piece without stressing/breaking it. So I may need a two piece that I can unbolt/disconnect in the middle and slide the halves off of the finished piece. Kind of hard to describe without pics. Also, would love to have your thoughts about mold materials (plaster vs. fiberglass) and release agents.
alanw6
Member
Michael, good questions. I'm going to have to give some answers later, as work won't allow me to type the response I wish to offer.
I'll post more detailed information later this evening.
I'll post more detailed information later this evening.
alanw6
Member
I DiDio I said:
This is a good online resource for materials and basic techniques, and I've seen it posted in many places.
It also highlights one of my points above. That is start small, and work your way up to more complex projects. If you notice on the site, there is not one of those projects actually completed. The sloppy initial approach made the finish work almost unbearable (trust me, I know!) and the project was abandoned.
Again, it's not too hard. You don't have to be a chemist or an artist. Just be patient and through trial and error you'll get pretty good. I pick up new tricks/techniques on every project.
Michael, I will answer your questions in detail later, just had a minute to chime in with my $.02.
Alan
04sleeper
Founding Member
Michael,Michael Yount said:
First let me ask you how strong does the bumper need to be? Is it just for looks or are you planning on having it take a hit?
If strength is not an issue you can use matting. It is very easy to work with and bends around corners easily. Also it can be torn into smaller peices easily. It works great for mold making.
Speaking about molds, you can use plain polyester boat resin that works just fine for resin and gelcoat for the first layer. Also polyester resin won't stick to masking tape or aluminum foil. You can use PVA (polyvinyl alcohol) release to release the fiberglass after you make the mold to reease the part from it. In order to make the mold you can just completely tape off the bumper with masking tape maing sure when you lay on the fiberglass it will pop off.
Michael Yount
Mustang Master
Thanks for the quick response. I intended to address strength requirements in my original request. These bumpers started life as the old 5-mph bumpers on pneumatic struts on my 82 Volvo. To clean up the lines of the car (how do you clean up a brick?), we've long since drilled the struts and let the air out - and pushed the bumpers up against the car -- looks much better. So they serve no protective purpose any longer.
Given that, the rear one needn't be strong enough to absord an impact. However, I don't want it flapping as I go down the road either.
The front bumper has to support an air dam which attaches to the bottom of the bumper. That dam sees pretty good aero load when cruising down the road at 70 or 80 mph. I may also want to cut some openings in the bumper and mount driving lights behind it. So I'm wondering about ways to reinforce the front bumper. Both can be pulled from the same mold. I've been thinking I could imbed some light gauge aluminum or steel strapping in the areas where holes will need need to be drilled to attach the air dam.
One thing I'm not clear on is how quickly does the resin set up once it's catalyzed. And, how many layers will it take -- I assume this is built up like lasagna - resin, imbed the cloth, saturate, more resin, more cloth, etc. How many passes does it take to come up with say 1/8" thick fiberglas?
Given that, the rear one needn't be strong enough to absord an impact. However, I don't want it flapping as I go down the road either.
The front bumper has to support an air dam which attaches to the bottom of the bumper. That dam sees pretty good aero load when cruising down the road at 70 or 80 mph. I may also want to cut some openings in the bumper and mount driving lights behind it. So I'm wondering about ways to reinforce the front bumper. Both can be pulled from the same mold. I've been thinking I could imbed some light gauge aluminum or steel strapping in the areas where holes will need need to be drilled to attach the air dam.
One thing I'm not clear on is how quickly does the resin set up once it's catalyzed. And, how many layers will it take -- I assume this is built up like lasagna - resin, imbed the cloth, saturate, more resin, more cloth, etc. How many passes does it take to come up with say 1/8" thick fiberglas?
Michael Yount
Mustang Master
Oh - can you imbed color in the glass? I don't want a gloss finish - I'm happy to paint to the finish I desire. But due to the amount of rock-chippage the front bumper will see, it would be great if the base color of the resin were black - so as black paint is chipped, it's not as noticeable.
BlackVert
15 Year Member
i was considering trying something like that for my car too, but time and financing have not presented themselves yet ...Roadblock said:
Michael Yount
Mustang Master
Roadblock - just do a google search under 'fiberglass' - you'll come up with more resources than you'll possibly know what to do with.
04sleeper
Founding Member
It really depends on what the temperature is and how much hardener you use to deternine the set time. This is usually done by trial and error with small peices.Michael Yount said:
It will not take you very long to achieve 1/8" or thick enough to get the strength you are looking for. I would say around 3 to 4 layers.
You can use your idea on reienforcing the bumper with light gauge aluminum or steel but if weight becomes an issue you can cut stripsor blocks of foam and glass around them. Like using "Divinycell Foam" for example. It is made from a PVC plastic and foam combination that bonds to the fiberglass when it is used with polyester resin. It actually melts into it somewhat to become one strong peice. It is super light and very easy to shape and work with. I have used it several times before. Also a good thing to use when trying to bolt anything to it is "T-nuts". You can drill a hole in where you want to mount, say a light for example, and put it in with some "Cabosil" mixed with the resin to make a strong type glue.
Yes you can imbed the color in the glass. It can be done in 2 ways. The use of Gelcoat, like a boat would use for example, or you can buy pigment for the resin that will make it any color you desire.Michael Yount said:
alanw6
Member
LOL. Just had time to write a response to you Michael, and read through 89sleeper's excellent answers. I wouldn't be doing anything but echoing what he said, so I'll save the bandwidth.
89sleeper, thanks for stepping in with your answers. You're right on the money. Any idea on when Dwayne's car will get its feature published? It deserves to be seen by a lot of people, the work is at a level I aspire and look up to.
Alan
89sleeper, thanks for stepping in with your answers. You're right on the money. Any idea on when Dwayne's car will get its feature published? It deserves to be seen by a lot of people, the work is at a level I aspire and look up to.
Alan
Michael Yount
Mustang Master
Thanks guys - I appreciate the advice. I'll just hook up with my local fiberglass suppliers and ask more questions, then forge in. Can't hurt anything other than having to make another one. Appreciate the note about pigments - thought you could do that but wasn't sure.
WE've got two big boat manufacturers here in town - there's likely some locals that know a thing or two about this.
Oh - I've seen some faux carbon fiber fiberglass - at least I think that's what it is. You can see the carbon (maybe) mesh below the clear coat. Have you messed any with this. I have to admit, I do like the look of it in black.
WE've got two big boat manufacturers here in town - there's likely some locals that know a thing or two about this.
Oh - I've seen some faux carbon fiber fiberglass - at least I think that's what it is. You can see the carbon (maybe) mesh below the clear coat. Have you messed any with this. I have to admit, I do like the look of it in black.
alanw6
Member
Michael,
check this website out: www.selectproducts.com
They have a fiberglass and a carbon fiber section (showing materials and some training videos). You can do either fiberglass weave for the "look" or go with real carbon fiber. The basic techniques are not too different, but advanced techniques start to differ.
I'm not too familiar with CF, but perhaps that link will help.
Your marine supplier is a good start, especially since the resin is much higher quality than the home depot/bondo brand. The wax content is much lower in marine resin, which is beneficial when it comes time to do the body work.
check this website out: www.selectproducts.com
They have a fiberglass and a carbon fiber section (showing materials and some training videos). You can do either fiberglass weave for the "look" or go with real carbon fiber. The basic techniques are not too different, but advanced techniques start to differ.
I'm not too familiar with CF, but perhaps that link will help.
Your marine supplier is a good start, especially since the resin is much higher quality than the home depot/bondo brand. The wax content is much lower in marine resin, which is beneficial when it comes time to do the body work.
Michael Yount
Mustang Master
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