Fiberglass cafe seat-Materials Needed? (81xs400 build)

[jmj166]

Hello all, i have looked through quite a few of threads from this section about making your own fiberglass seat. I decided i wanted to do this (over buying one) for the sake of learning. I have a general idea of what to do. But what i was wondering was....what kind of specific materials do you need to fiberglass your own seat. I know i'll need resin, but is there a certain type i should use, as well as a certain type of fiberglass to use. I've seen a bunch of videos and tutorials of people doing fiberglass with molds. But as pay day approaches (only a few more days ;D ) I figured i would have to order the materials from the internet as there aren't many...or any that i know of....boat stores around here. The only fiberglass type material or resin is that bondo repair stuff you find at lowes or walmart. Which i've read isn't good to use at all.

So if anyone has any experience, preferences, or just general information about fiberglass mats and resins to use and whatever else, i'd very much appreciate it.

and although it isn't neccessary, heres a picture of the current build...i just haven't had time to make a build page yet.



Uploaded with ImageShack.us

anyways, any info would be very much appreciated.

 

[jay_kent]

I've had good results this route

SM foam from Home depot. The pink or blue foam found in the insulation aisle is the stuff I've used. use a bread knife and a rasp to get it to rough shape you want and then you can use sandpaper to get to the final shape. If you're careful enough you can get it super smooth, a much better starting point than using pelletized foam. cover the foam with tinfoil or latex paint. Cheap resin will eat it.

and even with the store bought resin, a type from boat builders is to thin it out.
I've thinned out polyester resin using using Acetone. mixed at 10% per volume. So 300 ml of polyester resin I mixed in 30ml of acetone then added the 2% of hardener, 6ml then mixed it again. It took awhile before the acetone and resin were completely mixed. I found this amount worked for me to get a couple of layers down before it started to gel and the thinned resin mixture saturated the cloth/mat much more thoroughly and quickly.
Another thing I've done is to warm my can of resin, (I'm in the basement of a barn), in a tub of hot water. Flows better.

The best method that I've found that works is to lay a sheet of aluminum foil on a work surface and with chunks of fiberglass mat, wet it out completely using a paint brush, dabbing it works the best. This way you won't use too much resin and you'll see the fiberglass is completely saturated, then place it on your mold. dabb it with the paintbrush to get rid of any air bubbles. Once you've built up your layers to as thick as you want it. Roughly smooth out the high spots. It doesn't have to be perfectly smooth but should be close, then with the resin unmixed with acetone, paint on a couple of layers. This will give you a nice smooth surface without having to use bondo to fill in the all of the pinholes.

Make your mixture in small batches so it doesn't setup before you've had the chance to use it all.

 

[jmj166]

do you first put down a layer of fiberglass cloth, then start putting layers of fiberglass mat? also, i've seen continuous strand and chopped strand fiberglass mats, any opinion on what would be best, if not something else?

 

[Steve Zodiak]

Here's where I'm at with mine...

http://www.dotheton.com/forum/index.php?topic=18525.0

I'll be pulling the seat out of the mold tomorrow.

 

[Erik]

I might actually be able to help here. My other hobby are old fiberglass boats. HD/Lowes/Wally world resins are polyester type. Its fine. I use it on all of my boats. Build your mold like described before (I will use luan and foam covered in foil tape) and start with 2 layers of chopped strand mat (CSM). You can mix resin to hardner in equal parts. 1/4 of tube of hardner to 1/4 can of resin as an example. It has worked well for me and gives me a dry time of about 20-30 minutes. Do not try to mix more than you can work with in 5 minutes. Get the CSM the way you want it and pull it off dry. Use a cheap chip brush to paint a medium amount of resin/hardner mix onto your mold and then place the CSM on that. Proceed to use the rest of your mix and paint the CSM until it is completely saturated. Place your next layer of CSM on top of that and saturate that layer. Chip brushes are cheap so buy a few. Latex gloves are a must. You will wind up pushing CSM into all your little curves with your hands. You can use an old hard roller ( I have a dried up foam one) to try to roll the CSM flat if you have a flat surface. You can start your next fiberglass layup with the cloth if you want. If you are going to want it super strong for some reason, you could ebay a remenent of woven roving and lay that next. You MUST be sure that woven roving is completely saturated. If you do not get mat saturated, it may rise or lift. You can always finish with cloth, but I never can get it perfect. Pick a quality filler and sand away. Hit me up if you have any trouble. I live in Kansas City and have both 100 degree summers and below freezing winters and it always turns out the same.

 

[jmj166]

I might actually be able to help here. My other hobby are old fiberglass boats. HD/Lowes/Wally world resins are polyester type. Its fine. I use it on all of my boats. Build your mold like described before (I will use luan and foam covered in foil tape) and start with 2 layers of chopped strand mat (CSM). You can mix resin to hardner in equal parts. 1/4 of tube of hardner to 1/4 can of resin as an example. It has worked well for me and gives me a dry time of about 20-30 minutes. Do not try to mix more than you can work with in 5 minutes. Get the CSM the way you want it and pull it off dry. Use a cheap chip brush to paint a medium amount of resin/hardner mix onto your mold and then place the CSM on that. Proceed to use the rest of your mix and paint the CSM until it is completely saturated. Place your next layer of CSM on top of that and saturate that layer. Chip brushes are cheap so buy a few. Latex gloves are a must. You will wind up pushing CSM into all your little curves with your hands. You can use an old hard roller ( I have a dried up foam one) to try to roll the CSM flat if you have a flat surface. You can start your next fiberglass layup with the cloth if you want. If you are going to want it super strong for some reason, you could ebay a remenent of woven roving and lay that next. You MUST be sure that woven roving is completely saturated. If you do not get mat saturated, it may rise or lift. You can always finish with cloth, but I never can get it perfect. Pick a quality filler and sand away. Hit me up if you have any trouble. I live in Kansas City and have both 100 degree summers and below freezing winters and it always turns out the same.

This is really good info, sorry it took so long to reply. I've had little time to work on the bike btwn both jobs. Do you prefer polyester resin over epoxy, i've read a couple places about the two and am unsure of which would be best (or most simple) to use. great info though, thanks. i appreciate it

 

[Erik]

Epoxy resins do not smell as bad. There are some discussions that epoxy could be a better binder than poly. If so, then I will promptly sink next summer out on the lake. My ass won't feel that good as well from banging on the frame either, because I plan on sticking with poly. Its cheap, available, and has worked for me. I personally have never found an application where I really needed epoxy resins. I'm not saying that there are not applications for epoxy, but it would require me to order it in and pay more for it when all of my older boats have been built with poly. It's really up to you. Just by the looks of most factory seat pans that are fiberglass, it just looks like CSM layered. If you were worried about how many layers, just look up fiberglass lay up. You can skim the technical jargon and just get to the pics. Most start with CSM, then you can get cloth, back to CSM, and finish with cloth. If you are unsure about how strong that will be, order some woven roving in the lightest ounce and go CSM,CSM, roving woven, CSM, cloth. Cloth is not really strong as much as it will help with the finish. Add or subtract layers as you feel. Just be sure to saturate the fiberglass and mix batches that you can use in 5 minutes or so. I am NOT an expert. This has just worked for me. I found that I can only usually mix enough resin to do 2 layers of CSM or cloth at a time. I usually only do 1 layer of 18 oz roving woven at a time so I know it is completely saturated. Let me know if any of this helps...

 

[jmj166]

Epoxy resins do not smell as bad. There are some discussions that epoxy could be a better binder than poly. If so, then I will promptly sink next summer out on the lake. My ass won't feel that good as well from banging on the frame either, because I plan on sticking with poly. Its cheap, available, and has worked for me. I personally have never found an application where I really needed epoxy resins. I'm not saying that there are not applications for epoxy, but it would require me to order it in and pay more for it when all of my older boats have been built with poly. It's really up to you. Just by the looks of most factory seat pans that are fiberglass, it just looks like CSM layered. If you were worried about how many layers, just look up fiberglass lay up. You can skim the technical jargon and just get to the pics. Most start with CSM, then you can get cloth, back to CSM, and finish with cloth. If you are unsure about how strong that will be, order some woven roving in the lightest ounce and go CSM,CSM, roving woven, CSM, cloth. Cloth is not really strong as much as it will help with the finish. Add or subtract layers as you feel. Just be sure to saturate the fiberglass and mix batches that you can use in 5 minutes or so. I am NOT an expert. This has just worked for me. I found that I can only usually mix enough resin to do 2 layers of CSM or cloth at a time. I usually only do 1 layer of 18 oz roving woven at a time so I know it is completely saturated. Let me know if any of this helps...

this is very usefull information, i really appreciate it. I started trying to make the mold this past weekend but it came out much bigger than i wanted. so i'm probably gonna start over and use a different kinda foam and redo the measurements. I'm was just overall curious about peoples uses of epoxy vs polyester, from reading this i'll probably go with polyester. I can borrow respirator masks from work if smell is the biggest difference. I appreciate the info. this is exactly what i needed

 

[Erik]

In comparison, the poly stinks about the same as spray paint. Keep in mind that anything that you have to mix and get a chemical reaction to bond something else probably needs good ventilation. I would not do this in the kitchen of your studio apartment. 3M used to offer very affordable resperators with replacement filters. We would paint a car or a few hoods and then throw them in a zip lock bag. I would go back and finish what we were doing and then just toss them. They come in a plastic bag new. Unless you are really sensitive to the smell, just do it outside or with garage doors open. Just remember that it will stick to everything and its a PITA to get off. If you decide to shape the hardened fiberglass: 1) IT'S SHARP! (2) It goes everywhere... in your skin, eyes, and mouth...ect.

 

[urbandork]

I use floral foam called Oasis. Its really easy to form, shape, and shave down. After getting the desired shape i cover it with a layer of masking tape and then lay the fiberglass/resin on that using a thin layer of vasoline so the glass pulls away from the tape.

and in still working on this one

hope it gives you an idea.