Balsa fill?

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 1:13 am

When you refer to"balsa fill"do you mean actual balsa pieces fitted into gaps or a prouct like microfill.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 5:33 pm

Let me rephrase the question.When the term balsa fill is used is that a product ie:microfill,testors green,or a hobby specific wood putty or is it a technique? Either way would somone please elucidate.

supercruiser · Post by **supercruiser** » Mon Jun 09, 2008 5:43 pm

I guess that depends on what you are going to do with the model. For static display balsa fill can be all of the above. Any kind of putty would work. For flying... thats different. I think some folks use an elmers/ water/ talcum powder mixture. I've never tried it but, balsa dust (from your sanding operations) mixed with diluted elmers might be o.k.

What exactly are you trying to fill?

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 6:13 pm

Thanks super.Not exactly a task specific question i was just a little vague on the term and had come across it a few times in different posts.Was worried that there was some basic bit of information i was missing.Although as I proceed on my builds I will use this thread for advice on this topic.I am building with an intention to fly so I am interested in weight and warp resistance.Doas the Elmers water talk mixture resist shrinking?

supercruiser · Post by **supercruiser** » Mon Jun 09, 2008 6:40 pm

I doubt it has any affect on shrinkage/warpage. The talc mixture is actually used as a sealer. To reduce the porosity of the balsa and give it a smooth sheen when sanded. Like I said, I've never used it. Balsa fill, I suspect is mainly for static models, to fill gaps between surfaces or such.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 6:59 pm

I have used carpenters putty,fill,and spackle on other non aeromodeling projects they all strike me as heavy for an airworthy airframe.Without testing it mind you.The white glue and other ingredient mixture I will try .but white glue I have used tends to shrink ,unless the other substances in the mix curb this tendency I would fear warping.I haved used carpenters glue (the yellow one)for cabinet repairs and will fill a modest gap nicely but that was on mutch sturdier wood.I have ordered a jar of microfill because I saw it used on the SFA site.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 7:02 pm

Do you reccomend that for doping?50%h20 50% glue ?%talk

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 7:17 pm

Keeping in mind the three kits I have on my board now will be the first three I will ever have put a covering material on. So its quite possible I'm fretting over nothing as far as warping is concerned.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 7:24 pm

My previous kits are all bare bones in my cabinet .Sort of an ornithilogical banana shaped beastiery.Once I have refined my technique I will crack and rebuild and advice on fillers will be quite useful

supercruiser · Post by **supercruiser** » Mon Jun 09, 2008 8:39 pm

For doping, I use spray can Clear Acrylic Lacquer. After the tissue is applied with glue. I shrink it with rubbing alcohol. The talc mixture is for sealing the balsa,just before you apply tissue. You apply some talc mixture, lets say on the wing leading edge, let it dry. Sand it smooth. maybe apply a second coat talc mixture, let it dry, and then sand smooth. This gives a nice surface for the tissue to adhere to. There is a thread somewhere around here about doing this. Maybe a search for the word talc or talcum will yield something.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 9:21 pm

All I pulled with talc was a thread from Jedinak on wet tissueing and glue stick.Kitty mentions a mix of thinner and talc for a sanding sealer and Steve mentions furniture polish.interesting but Im getting off topic I think I'm going to wait for the microfill ,and try your advice with the white glue and talc.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 10:46 pm

Super c can you give me a trade name on the acrylic laquer sounds quicker simpler and more efficient for sealing than doping .I'm guessing you use alcahol because it evaporates quicker.

mikethe hamster · Post by **mikethe hamster** » Mon Jun 09, 2008 11:06 pm

got a lot more info under talcum search mark1996 posted a thread on sheeting with balsa and kitty basically told him everything I wanted to know the thread stands on it's own so I wont repeat the information to me a hyperlink sounds painful and sports related .Just search under talcum for any future builders following this thread it will be worth your time.

SteveM · Post by **SteveM** » Tue Jun 10, 2008 12:03 am

NHP Micro-Fill is temporarily discontinued and you may be waiting a long time for it. Hobbylite by Hobbico is a similar product though discerning people like David Duckett find Micro-Fill to be superior. Also, Jet Model Mate by Goldberg appears to be an ok substitute until Micro-Fill production resumes.

Static display planes can use just about anything sandable for filler, but a flying plane needs to use a lightweight product like one of the three I mentioned above.

Poppy, the master filler, uses two fillers and a primer to get a very smooth finish for his static display models as shown here.

mikethe hamster · Post by **mikethe hamster** » Tue Jun 10, 2008 12:19 am

Thanks steve the shop I ordered from said that it was one of there last tubs and they couldn't get it anymore .