I was assembling a recently purchased Sig Senior Kadet ARF. I didn't get very far. I got the servo in the left wing, started to do the left wing servo. The ribs holding the servo, and the ones next to them were crushed. Called Sig, they asked me to pack it up and send it back to them. So I started on a Sig Rascal 40. Got both aileron servos installed, the fuel tank finished, then the engine mount installation. Only the left from bolt would go in all the way. The other three would only partially go in. Apparently when they fuel proofed the firewall area, they got some of the goop in the blind nuts. What do I do about this. Can I get some hex nut 3.5 mm nuts and try to force them through the stuck parts? I sure don't want to call SIG about this plane too. Or is there some other way to clean them up? Thanks for your help.

When I was fuel-proofing my fire wall I did the same thing - got epoxy inside the blind nuts. All you need to do is make a run to your local hardware store, or maybe even you local hobby shop, and pick-up a tap and drill set. They're about $3. I would bring a motor mount bolt with you to get the correct size. Keep in mind that most of the hardware in ARFs are metric. In my particular case the bolts were 4mm. Then just drill out the epoxy with an undersized bit, taking care not to damage the blind nuts, and run the tap through. Everything should be good after that. Good luck.

A little trick I have used before if you can get the bolts started a little bit is to get another bolt of the correct diameter only longer. Cut two v- grooves in the end of the bolt two or three diameters long. Then take and screw the bolt in until it gets tight working it back and forth. When it gets too tight bring it back out and clean the grooves. You may have to run it in and out several times but this will work, just don't force it, go a little at a time. This will save the expense of a tap.
Fred

Fredscz, sounds like he has a pretty good method, short of buying a tap. I would like to add to that, if you heat the bolt, it will go in little easier, then just follow the instructions Fredscz gave, and the bolts should not get tight enough to make the blind nuts turn inside the firewall. I use a butter knife to mix epoxy. When it is dry, I use my heat gun to heat the dried epoxy, it crystalizes and scrapes right off. If you have a torch, you might want to heat the bolt with it. Always happy to help if I can. Garry

A tap will only cost you two bucks at the auto parts store, and it will clean up the threads in about 30 seconds. These other methods will work, but why screw around with it for hours and run the risk of breaking the model?

Well, I went to several auto parts stores. They never heard of a 3.5mm tap. I went to the Sears Hardware store, no luck. I searched on internet, out of hundreds of listings for 3.5mm tap, I found one place with 3.5mm taps, Great Bay Model Yachts in Las Vegas. I called Sig about this problem, Scott said that the 3.5mm meant it was a 3 mm bolt with 5 pitch, or words to that effect. and to use a 3mm tap to clean the blind nuts. I went looking for a 3mm tap here in Brookville. No one had them. I called GBMY about the 3.5mm tap. They were busy. Then I screwed on of my 3.5mm screw in one of the blind nuts to see if my soldering iron would heat it up enough to melt whatever was there. It didn't help. So I unplugged the iron, and tried to remove the screw - I burnt my fingers slightly, but that unlocked my brain. I went to my goody box and got a 3mm screw, and it went right in with no problem - It took me one and a half hours to remember what Scott from Sig said about the blind nut. I've tried all four blind nut, and the 3mm screws all work. PROBLEM SOLVED. But the manual from the kit says that these mounting bolts are 3.5mm Philips head bolts. Oh well, you just never know. Anyway, thanks for all you suggestions. Now I will try to see what else I can screw up.