07/16/2015 at 4:05 pm #42354
I see that fiber glass clothe is available in a number of different weights, 1.5oz, 2.0oz, 4.0oz etc… I have never worked with the stuff before and I have seen it said many time that the nose/pylon area should be reinforced. So what weight cloth should be used. Is carbon veil an alternative?
dlh9837007/17/2015 at 5:59 am #55340
1.5 oz. should be fine. Here is a little trick to use to apply the fiberglass cloth. Take a sheet of CUTRITE brand wax paper. Use CUTRITE brand rather then the generic brands as it has more wax on the paper, which acts like a release agent. Take a can of 3m77 spray adhesive and spray a light coat on the wax paper. Take the fiberglass cloth and lay it on the 3m77 spray adhesive side of the wax paper, then spray a light coat of the 3m77 over the fiberglass cloth. This coat of adhesive keeps the fibers of the glass cloth from unraveling while you cut it to shape. Use a sharp knife to cut the cloth to the desired shape. Spray a coat of 3m77 on the firewall, then take the cut out cloth with the wax paper attached to it and place it on the firewall. The wax paper will be on the outside. Use your finger to rub on the wax paper to seat the fiberglass cloth and remove any air bubbles. Remove the wax paper and use thin Hot Stuff ca. to glue the fiberglass cloth to the firewall. Before applying the Hot Stuff, take a zip lock plastic bag and cut it open to form a large single sheet. A single layer works best for our purposes in this case. The best way to apply the thin Hot Stuff is simply work the ca. bottle back and forth and flood the fiberglass cloth, if you see any white spots on the cloth as you work the glue, just add some more ca. As you apply the thin Hot Stuff, take the plastic bag and place it over the fiberglass cloth as a barrier, to protect your finger from sticking to the Hot Stuff as you rub the Hot Stuff to help stick the cloth to the firewall and remove any air bubbles. Do a small section at a time to allow time to complete the process. This method can also be used on dihedral joints or on the leading edges of a high thrust model fuselage, like a STARDUSTER. After the fiberglass cloth is applied, you can then use some epoxy over the cloth for added strength. You do not need to use epoxy over the fiberglass cloth on the dihedral joints. On dihedral joints you can use 3/4 oz. cloth. The use of 3m77 adhesive will have no effect on the Hot Stuff from working as it should. I have worked with fiberglass since the 1960’s as I had a fiberglass business working on CAN-AM sport cars and building fiberglass funny car bodies in the 70’s. Based on all my experience this use of Hot Stuff ca. is one of the easiest ways to apply fiberglass cloth on models. You can make small fiberglass parts, like cowlings, in minutes without having to use fiberglass resin using this process and the parts are lighter also. if you have any questions. PM me.
Mike07/17/2015 at 3:06 pm #55341
Thanks very much for the information and the excellent write up.
Daniel07/17/2015 at 7:02 pm #55342SIMON BLAKEParticipant
My understanding has always been that nitro dissolves Hot Stuff and similar cynoacrylate glues, so they shouldn’t be used on firewalls.I always use epoxy. My method is to cut a strip of fibreglass cloth about a half to one inch wide depending on model size, smear epoxy around the part of the fuselage and firewall that you are reinforcing, wrap the fibreglass cloth around, and then wrap a strip of wax paper over that, with masking tape also wrapped around everything until it is dry. I just use a stick to spread the epoxy and work it into the cloth. I do tack one end of the fibreglass strip in place with hot stuff so it doesn’t move. Fibreglass weights range from 1/2 ounce on the smaller power models to 1-1/2 ounce on the larger ones.
Regards, Simon07/17/2015 at 10:59 pm #55343
In my write up about using Hot Stuff to apply fiberglass I mention putting a coat of epoxy over the Hot Stuffed fiberglass cloth on the firewall. Nitro methane will dissolve Hot Stuff in a “liquid state”. It has a slight softening effect when cured. A simple coat or two of fuel proofer will provide all the protection that is needed.
Mike07/28/2015 at 5:28 pm #55344
Tried this technique out this weekend with very good results.I wonder if a coating of epoxy over the Hot Stuffed fiber glass is required if I was going to paint the fuselage/firewall with KlassCote epoxy paint anyway.
Dan H07/29/2015 at 12:13 am #55345
I only mentioned using epoxy over the fiberglass on the firewall, because some people are afraid they need the added protection over the Hot Stuff or any ca. for that matter. Its more a feel good measure then anything else. As long as you fuel proof over the fiberglass, epoxy is not needed. Just sand the fiberglass to roughen up the surface to get good adhesion for the paint. 120-150 grit sandpaper will do the job. If you prime the fuselage using KlassKote primer, then when it dries, take 400 wet sandpaper and wet sand the primer. The surface will much smoother and there will be less sand scratches in the primer which would show up in the top coat.
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