Best way to install horizontal stabilizers

This becomes more of a challenge with vac form models. There it usually helps to make a spar that goes all the way through, and has the right dihedral/ alignment.

After plunging 30,000 feet, have a 62 deg. nose down pitch and 90 deg.roll, these idiots called LAX to report conditions normal. Only then did they see that some of the landing gear were dangling under the plane and significant parts of the hydraulics were drained.

I'm with Greg.  Just keep it simple and eye-ball it.  You have to hold them by hand for a few minutes while the bond sets up, and adjust them as needed during this time.  

GMorrison

My father took me to see a JAL 747 that had suffered an uncontrolled rapid descent enroute to SFO.

The horizontal stabilizers were bent up at a very noticable angle beyond spec.

I'd certainly take issue with the assertion that they were "never perfectly level". Obviously the surfaces are usually tapered, but there are way too many different examples to examine. Example: Horsa glider.

And quite a few have anhedral.

 

the B-17, which this original question is about, has a pretty squared off alignment of the vertical to horizontal tailplanes.

My father took me to see a JAL (Edit: CA) 747 that had suffered an uncontrolled rapid descent enroute to SFO.

The horizontal stabilizers were bent up at a very noticable angle beyond spec.

I'd certainly take issue with the assertion that they were "never perfectly level". Obviously the surfaces are usually tapered, but there are way too many different examples to examine. Example: Horsa glider.

And quite a few have anhedral.

Silver

Lots of photos of aircraft ww2 on up rear tail flats or planes were never perfectly level.Do the best you can.I.P.M.S. Won’t get mad .

 

No, they won’t get mad at all. But if you are entering the build into an IPMS contest, basic alignment being off will get a model eliminated from consideration as part of the basics. 

Lots of photos of aircraft ww2 on up rear tail flats or planes were never perfectly level.Do the best you can.I.P.M.S. Won’t get mad .

This is how I do it and it works every time:

Set the fuselage down and it helps if the wings and mains and tail gears are on to get a straight and even alignment. Slide the stabs in place and hold them up with whatever will keep them at the correct angle, like small foam blocks that can be cut to size. I even use paint bottles specially the Humbrol tins. Use any object that will work. I have a small metal ruler that I use to measure to make sure both stabs are even to the workbench surface. Use some Tamiya thin glue and hit it several times so the join is flooded and let it cook for a few minutes. You can even try to carefully squeeze in the stabs and the melted plastic will in most cases take up the gap. Re check the angles again and let it cure overnight resting on the blocks.  

I like to use Plast I Weld with a Tiuch N Flow applicator for this but it takes a lot of practice to master the use of the Touc N Flow tool so for now go with the Tamiya thin glue in the green bottle.

Rambo

 

 

the Baron

 

 

BlackSheepTwoOneFour

.... Perfect Plastic Putty is NOT glue. Glue with liquid glue, let dry. Fill in with PPP. Let dry. Wet sand with water. Simple as that.

 

 

 

Is there a problem wet-sanding with Perfect Plastic Putty, since it is water-soluable?  I thought people have reported elsewhere in the forum, that applying water, even after the putty had appeared to have cured, wound up liquefying the putty again.

 

 

 

 

as long as you don't flood it with water but enough to keep the paper moist.

 

Exactly. As long as you don’t saturate it, you’re fine. Sometimes I’ll use a sponge or small sanding blocks.

the Baron

 

 

BlackSheepTwoOneFour

.... Perfect Plastic Putty is NOT glue. Glue with liquid glue, let dry. Fill in with PPP. Let dry. Wet sand with water. Simple as that.

 

 

 

Is there a problem wet-sanding with Perfect Plastic Putty, since it is water-soluable?  I thought people have reported elsewhere in the forum, that applying water, even after the putty had appeared to have cured, wound up liquefying the putty again.

 

as long as you don't flood it with water but enough to keep the paper moist.

I'll use tape, by the way, to hold horizontal stabilizers in place while the adhesive sets up.

BlackSheepTwoOneFour

.... Perfect Plastic Putty is NOT glue. Glue with liquid glue, let dry. Fill in with PPP. Let dry. Wet sand with water. Simple as that.

Is there a problem wet-sanding with Perfect Plastic Putty, since it is water-soluable?  I thought people have reported elsewhere in the forum, that applying water, even after the putty had appeared to have cured, wound up liquefying the putty again.

Don Stauffer

I often make sort of jigs for that job.  I weight down or tape down the fuseage so it fits level.  then I cut blocks of particle board or wood to sit under stabilizers so they fit level.  Then I apply glue and stickt them in place and wait for glue to dry.

 

Or use Blu-tack. I‘ve tried sticking a blob of it at the fuselage just under the stabs, especially when fit is loose. Position stabs with Blu-tack as support, with the advantage that angle can be adjusted to your satisfaction. Then apply liquid cement at the seam. Carefully remove Blu-tack after cement has dried. If necessary, apply liquid cement at underside of seam of stab/fuselage joint. 

I built that model a while ago. I just took a look at it and I was amazed at how big the horizontal stabilizers are. I can see how it would be difficult keeping them horizontal until the glue cures. I agree 100% with Don regarding how to keep the stabilizers level. An option to using wood would be foam wedges.

I often make sort of jigs for that job.  I weight down or tape down the fuseage so it fits level.  then I cut blocks of particle board or wood to sit under stabilizers so they fit level.  Then I apply glue and stickt them in place and wait for glue to dry.

twodb

(yes, pics do seem show them pretty much "flat" w/o dihedral).

I agree with that, they usually are. I'm not sure why I mentioned dihedral in my post.

Tube cement is less potent than liquid cements. The tube stuff is partial carrier medium, a resin of sorts, and once the glueing agent evaporates away, it leaves the resin behind. The carrier resin has very little bonding strength. I’ve had old models literally fall apart at the seams as the resin deteriorates with age, because the plastic was not welded together by the bonding agent in the glue.  While the liquid stuff is all of the actual bonding agent. After a time it evorates away as well, but leaves less residual mess. Some liquid cement brands are better and hotter than others. I have gotten away from Testors liquid cement and moved to other brands due to quality control problems with that stuff.

goldhammer

If you make about 3 applications of Testors or tamiya liquid glue, one after another on both mating surfaces, it will soften enough to push them tight and get a good bond.  Helps with gaps as well.  If you get a slight ridge of plastic squeeze out on the joint just sand flush

 

If you make about 3 applications of Testors or tamiya liquid glue, one after another on both mating surfaces, it will soften enough to push them tight and get a good bond.  Helps with gaps as well.  If you get a slight ridge of plastic squeeze out on the joint just sand flush

All of the above, plus, if the mounting tabs are a loose fit in the slots, shim with plasttic strip of the appropriate thickness and/or add support tabs to the inner structure.

Somebody once taught me our eyes can work better than measuring and tools sometimes. I think horizontal stabs on model airplanes is one of those times.

Me, I apply glue to both of them, and sighting right down the nose and using the tail for perpendicular reference put the dihedral where it looks right and hold still for a minute. Done.

Check the fit of the mating surfaces. Sand down the contact points to give a more solid fit. Check your progress repeatedly until you get it as good a possible. Then glue them in place.

Hi,

I have never built that particular model so am unable to address it directly.

Getting that angle right though is a key to having the model look correct.

Glancing at drawings of G's online, for what they are worth, the stabs look to me to be pretty straight across.

Can you glue them with solvent and then go back with putty to correct any gaps?

Oy.... Perfect Plastic Putty is NOT glue. Glue with liquid glue, let dry. Fill in with PPP. Let dry. Wet sand with water. Simple as that.