Polyester Resin instead of CA and Epoxy
 

Has anyone ever used polyester resin (fiberglass resin) to build their plane?
I'm about sick and tired of the current quality of two part epoxy resins (like 20 min epoxy in the twin tubes).
I've always had great luck with wood and fiberglass resin in the past ( on my real boat), so I think I'm going to build my new HoB P-51 using poly resin instead of CA glue.

I'm sure i'll have to use CA glue to tack some pieces in place, but will finish with poly resin on all joints and such.

It dries Better and Harder than 20 min epoxy (which dries kinda rubbery). And poly resin is very strong.

Thoughts?

RE: Polyester Resin instead of CA and Epoxy
 

I use polyester resin and ¾ ounce cloth for finishing. I find it easier to use than epoxy. You can see how I use it here http://www.rcuniverse.com/forum/m_3973867/tm.htm

RE: Polyester Resin instead of CA and Epoxy
 

very brittle and very heavy you would be better off using titebond 2 or 3.

RE: Polyester Resin instead of CA and Epoxy
 

Aerowoof is right, Use titebond or good old Elmer's. I have used fiberglass resin on my firewall as fuel proofer & also, on my wing joints I always use it with the fiberglass cloth. You're right, it's easier to work with than epoxy. I've done a lot of "glass work" Vettes , boats etc.& by it's self it wouldn't be strong enough for stress areas. It actually gets it's strength when you use it with the fiberglass cloth .

RE: Polyester Resin instead of CA and Epoxy
 

The smell and the lack of a suitable cleanup for tools and such, along with the issue of heat generated during cure, weight, smell, Did i mention that before??

I built my first RC airplane fuselage from glass cloth and Polyester resin almost 40 years back. It was a resounding failure. I was told that you could place the brushes in a plastic bag and put them in the Frig for use the next day. It does work, but you can't eat or drink anything that was in the Frig when you put the stuf in. Let it be known that I didn't get a good nights kiss from the keeper of the Frig, my spouse, for several weeks, On ocasioon, I am still reminded of that foolhardy experment.

People tend to build on suscessful processes. Those that were not so successful tend to get swept by the way side. Epoxy, CA, Gorilla Glue, Tightbond, Elmers, and a couple others all have their proven place in building of models. While Polyester will work, the side issues and the results havn't brought to the use of the other items just mentioned. For stuff like cowls and wheel pants, it is a good choice, IF you have the molds and stuff to make use of it.

There was a very good article on laminations in one of the magazines in the last few months. The Mix of two, not very strong components, IE poly and glass resutlts in a strong finished product. Poly by its self is brittle and not very strong. Glass is also not very strong and will break. Combined, the give a strong finsihed product. I personally dont' want to mix glass and poly for an adheisive for my model work.

Don

RE: Polyester Resin instead of CA and Epoxy
 

Huh??? Poly Resin is about the most easy to work with. It smells great, the drying time is tunable to your liking, and clean up is as easy as a cup full of acetone and a few paper towels.

Balsa and poly resin are incredibly strong. The balsa takes the place of a fiberglass sheet. Balsa soaks up the resin very nicely and becomes a rock.
I'm not talking about using a gallon of resin here, but using a small brush and putting it on like you would epoxy.

RE: Polyester Resin instead of CA and Epoxy
 

you asked and were given good advice good luck .the planes I built with titebond or elmers glue all date back to 1970 and no joint failures after all these years.let us know how long your joints last and how much they weigh

RE: Polyester Resin instead of CA and Epoxy
 

is titebond a glue that I can pick up at home depot?

Are there any glues that I could use that dry epoxy hard that I could pick up at home depot?

How hard does titebond dry?

RE: Polyester Resin instead of CA and Epoxy
 

Tightbond is a standard in wool glues. Any hardware will stock it.

As for "Drying epoxy hard", I'm not sure what you are getting at. From a hardness standpoint, epoxy isn't all that hard. It is tough and bonds to wook well. Some epoxies dry rather rubbery, but still have good bonding strength. The slower it dries, the better penetration into the soft wood.

Tightbond is a glue that you can clean up with water before it drys. After, it is near water proof. It will sand some what easier than epoxy so that is a plus for it. I mix up a small bottle using about 7/8 ths Tightbond and 1/8th distilled watter. This gives a better penetration for the balsa. 3/4 to 1/4 is a little wetter than I like. Some applications, IE cap strips on ribs, I use straight tightbond as it is less likely to run.

I just finished a 60" wing for my Ruperts Dad, using only tighbond. There were a couple areas where it was slower that squirting CA, but in the end, it has turned our very well. The D tube sheets were left to dry overnight, but most of the other joints were ready to be moved in a couple hours. If you plan your work ahead, it doesn't really slow you down any. You also gain in the end as there is little dried glue cleanup required.

I have also heard the argument that it gives a much lighter weight as a great precentage of the volume evaporates of as it cures, where epoxy retains all of it's wet weight and CA keeps a high precentage. From a structural stand point, there are places for all three on your bench.

Doing the Ruperts Dad wing, I cracked the light LE sheeting and repairing it, I used thin CA as it would penetrate the wood better. THe down side is any CA that hardens external to the wood that needs to be sanded smooth. I made a pleasent discovery. If you you wet or dry 320 grit paper glued onto craft sticks (popcile sticks) it is abrasive enough to cut the hardened CA, but fine enoght not to be agressive on the soft balsa. I found that you can sand the CA right down to the balsa with minimual cutting of the wood. Garnet paper will not do this.

Don

RE: Polyester Resin instead of CA and Epoxy
 

Just like to jump in here with a quick question about Poly Resin. What can I use to thin it with? The viscosity out of the can is often thicker than I would like to work with. (I generally buy the body repair quart can locally.)

RE: Polyester Resin instead of CA and Epoxy
 

Sig I think has modeling polyester resin still. The auto/hardware stuff has thickeners in it that make it 10 times heaver than the other. Finishing epoxy or poly is the way to go now days.

RE: Polyester Resin instead of CA and Epoxy
 

Z-poxy finishing resin with 3/4 or 2oz cloth works
quite well. Sands easy and is very lite.

Regards,
Roby

RE: Polyester Resin instead of CA and Epoxy
 

As a straight adhesive, polyester resin would be considered too brittle. It is also hazardous, and must be used in a well-ventilated area. The activator is also hazardous. It seriously damage eye tissue if you get it in the eyes. It really isn't the best thing for general building. It's a very good product, though, for specialized areas, such as preparing a surface for paint, adding strength in localized areas, and so on.

Also, it makes a good substitute for epoxy in many areas because it's lighter.

As for epoxy, just because its smell isn't as offensive as other materials doesn't mean that it doesn't have some hazards associated with it. Inhalation of the vapors can still be toxic, and you need to be using it in a well-ventilated area, too. I know of a person who is so allergic to epoxy that just being in the same, large room with uncured epoxy caused severe physical reactions. Tolerance of epoxy usually decreases as exposure increases. People who have done a lot of building of molded homebuilt aircraft have found themselves sensitized to epoxy during the project, and wound up having to use more and more safety gear to protect them against reactions to it.

Just about the only glue you don't have to take special precautions with is the water-based aliphatic or casein glues, such as carpenters' glues and ordinary white glues. They are safe enough that you can give them to small children to play with.

You can easily check this out by doing a google search for the MSDS of any product.

RE: Polyester Resin instead of CA and Epoxy
 

I'll add this as I don't think anyone has mentioned it:

polyester will not cure properly if applied over just about any other chemical, particularly glues- elmer's, CA, etc. Epoxy will.

RE: Polyester Resin instead of CA and Epoxy
 

I would use anything but polyester resin. I used it quite a bit when I was in the Air Force and became quite sensitive to the odor. A good friend in the same career field repaired corvette bodies as a part time gig using polyester. It killed him. If you do use it, ventilation is key as well as masks and gloves. Polyester resin uses methyl ethyl ketone peroxide to start the curing process and either benzoyl peroxide or cobalt napthanate to accelerate the cure. Most commercial resins come with the accelerator already mixed in. Generally, it is the cobalt napthanate which gives the resin it's pinkish hue.If you mix it too hot, it becomes quite brittle and week. The left over resin on the cup can even become a fire hazard and toss splatter all over the shop. Epoxy resin is much stronger and less toxic. Take the time to clean everything, be fanatic about mixing proportions and thoroughly mix the 2 parts before application