Mark's TN Hawk Build

[Mark Elen]

Hi Nigel,

No, I didn't, but thinking about it now, I could have set them up on my mill and whipped a chunk off the offending bits.

Unfortunately, I can't stick it back on now😂

Cheers

Mark

[Mark Elen]

Tonight's little session was to glue the last skin on and throw a coat of paint on the servo mounts. I gave the primer a quick sand with a 1200 block and then gave them a blast. The Model Air range from Vallejo is supposed to be pre-thinned to go straight into the airbrush. I found it a bit spattery, so thinned it a little more. It went on beautifully, they are now sat drying. I've got a little 'fish eye' on one of them, not surprising as I gave it a final clean on my jumper (and I've been using silicone today at work)😁

I'm going to have to take cleanliness a bit more seriously when I'm painting.

Cheers

Mark

[Mark Elen]

Some more done today. That red is a little out in that it is too dark. I can play about with that later. The last skin is now dry, so I cut out the retract hole and the servo holes, the servo holes are just rough at this stage. When I glued on the bottom skins, I made sure that there was no glue whatsoever on the bearers, just on the ribs.

The plan was, to mount up the plates and cut around them to allow the plates to sit flush on the bearers. It worked out pretty well. I then ran a bead of superphatic around the cut-out and it wicked in nicely.

Cheers

Mark

[McG 6969]

Super neat work as usual, Mark.

Finally, I'm asking myself if it was a good idea to convince you to be part of the upcoming Fury Classroom.

I already realize now that I will be the only one to 'receive' all of Danny's board erasers right to my head... ppfff.

Cheers

Chris

[Mark Elen]

Hi Chris,

Thanks for dropping by and for your kind comments. Looking at your Vimicote build, you are doing a great job yourself in being neat. Im sure there will be an eraser or two heading my way! 😁

Cheers

Mark

[Mark Elen]

I managed a half hour tonight. I needed something to go right, as I had a mishap last night. More on that later. I decided to attack the leading edge. Measured the sweep angle at 26 degrees and halved it, then set up probably my favourite piece of workshop equipment, the disc sander. (I seem to spend a lot of time at it each building session)

I can honestly say, this is the one piece of kit that makes precise work easy. Within a couple of minutes I had all 3 pieces ready to glue on

The piece above has a 13 degree mitre one way and a 1 degree mitre the other to allow for the dihedral.

Once it's sanded to shape and covered, nobody will see it......😂

Now to last nights failure. The paint has gone off, but it has dried both too dark and fairly dull. I have pretty much decided to bin the idea of covering with film and instead to have a go at covering with lightweight glass and poly-c. Then the whole lot can be painted and there is nothing to match. So, to bring up the dull red, I thought, 'I know, I'll give it a light T-cut and see if it shines up....

Well, that didn't work out too well. 😂😂 I guess model acrylic doesn't like T-cut.

I have some Vallejo gloss varnish, I'm going to try giving the other one a blast over with that and see how it looks.

Cheers

Mark

[Martin McIntosh]

Almost glad (joking) that it was not just me who had problems finishing this model. If you want some of the Ferrari red to match the HK covering I have loads leftover. It must, however, be sprayed on top of a base white coat of some sort.

[Mark Elen]

Hi Martin,

Many thanks for your kind offer. I want to perservere with what I've got, I'm a sucker for punishment😂 But I will keep it in mind if it all gets too much.

Had most of today flying with the Ballerina and the Viper. I'm now getting comfortable with the Ballerina, in that I'm not constantly on edge with it and relaxing whilst I'm flying it. The Viper is another story. I bought it to get some EDF experience, and although I don't find it too difficult, launching on your own is a hit and miss affair - especially today with no wind. I've been underarm launching it and had no trouble....till today. I managed ok whilst I was on my own, but as soon as I had a couple of people watching, it all went wrong. Thankfully, one of the guys (thanks Mark!) helped out hand launching it for me. Thanks again goes to Mark for the Cyano when I got it wrong with a landing and snapped the nose off. Half hour later and it was back in the air. I'm reminding myself tonight that it is what I bought it for, to make the mistakes with it so that hopefully I won't make them with this....😁

Got home and sanded the LE on the hawk to the same profile of the sheeting:

I used the trick with masking tape to stop me from sanding the sheeting down. Now need to sand it to a radiused profile, not looking forward to that as it will be a bit 'freehand'. All in all, a good day.

Cheers

Mark

Edited By Mark Elen on 14/04/2018 23:27:15

[Mark Elen]

A little more done tonight. The night before last, I laminated the tips from 1/2 and 1/4 then last night I glued them on. Tonight I've sanded them down to the wing profile, again I used masking tape but this time I also used brown paper to stop me from sanding the wrong place. All in all, I'm pleased with the result.

I used the long bar sander, and found by resting most of the bar along the wing, I used the piece in contact with the tip almost like a small sanding block, the length along the wing stopped me from sanding too deep.

Flaps and ailerons next. I really ought to get the other servo holes cut out properly too.

Cheers

Mark

[Geoff Gardiner]

Coming along nicely Mark - keep up the good work.

[Biggles' Elder Brother - Moderator]

Nice work Mark it coming along really well.

Regarding the sander; Tony's designs are great but I always feel that, due to his construction methods, I'm carving the model out of a solid log and a lot of balsa ends up as dust on the floor!

BEB

[Mark Elen]

Thanks Gents for the kind comments. Got home from work today and got started on the Starboard Flap and Aileron. I've decided to build these as a pair and then separate once complete. The CNC set includes 6 off light ply riblets. I've been pondering if these go in the same place as the light ply ribs, or if they go at the ends of the flap and the inboard end of the aileron. The ends won out in the end.

They don't fit too well, so they got the finagle treatment. The sander is currently set up with the compound settings that each riblet will need to be persuaded to fit.

The leading edge got a 4 degree mitre put on it to match up with the riblets, I also sanded in the hinge locations for the flaps, I did the same on the trailing edge of the wing whilst it was going together.

Cheers

Mark

[Mark Elen]

Not a lot done tonight. I've signed up to Ride London, (100 miles in less than 8.5 hours) in aid of Macmillan Cancer Support in July, so I'm getting into some serious training. 27 miles done this evening in 1hour 50.😁😂

I did manage to sand down one of the support blocks for the flap horn. Another thing I've been umming and aarring about. Do I make it from balsa and have the plastic plate on top, in the end, I decided on birch ply, so that I can use some short servo screws and not see anything on top. I was concerned about the weight, but after sanding it came out less than 1g.

Cheers

Mark

[Mark Elen]

The build is still progressing, although a bit slower now.

Got the starboard flap and aileron roughly to shape and hinged up. It still needs some fine work doing but it's taking shape.

Cheers

Mark

[McG 6969]

Still following your splendid work, Mark.

Did you have a decision made regarding the covering colour and 'darker' red paint yet? Wouldn't it be possible to glass with hard varnish and paint the entire model? Daft question very probably...

Cheers

Chris

[Martin McIntosh]

With hind sight that is what I should have done.

[Mark Elen]

Hi Gents,

That is pretty much what I have decided on Chris. I've bought a kit from Bucks Composites with 8 square metres of 25gsm cloth and their 'Single part coating system'

I'm really looking forward to giving this a go. The plan then is to paint the whole lot, that way everything should match. (Famous last words😂

Martin, thanks for your comment, it's good to know I'm not doing something daft.

Cheers

Mark

[Martin McIntosh]

I shall be very interested in seeing if this single part coating system sticks the stuff down well since the acrylic type I once tried a long time ago did not.

[Mark Elen]

Hi Martin,

It's a new experience for me, so we will see how it turns out. I've quickly run up a test piece and it has had a first coat, it has wetted out the glass and it seems to be down to the balsa, it's going to need a few more to fill the weave though.

Im looking forward to some destructive testing once this is done. 😂

Cheers

Mark

[Mark Elen]

Tonight I put another couple of light coats on the test piece, they were dry in about 10 minutes each and I've just tried to pull the glass cloth off - 3 hours after the last coat went on.

It has pulled off, but it wasn't easy and it has brought a very fine coat of the top layer of fibres with it.

I have seen on another thread about using sanding sealer first, I'm now wondering whether to run up another test piece and try it.

Cheers

Mark

[McG 6969]

Hi Mark,

It's not that easy to judge just by some pics, but it seems to me that your glass is still very 'flexible' if you can curve it like it appears. I think quite a part of your resin - or whatever Bucks are selling - just 'disappeared' in the balsa by capillarity.

If you want maximum strength you should use polyester resin (2K) together with some peel-off sheet, but in this case I believe a water based solution is far easier and better for weight saving.

If you allow me, here is what I should do:

1/ apply a really thin coat of PVA diluted 20-25% (or commercial sanding sealer) like for brown paper covering. Let it dry completely and sand back with medium paper (240?). This closes the grain nicely.

2/ lay your glass cloth on the surface and ‘paint’ - starting from the middle to the edges - with your Bucks stuff or a water based hard floor varnish (Ronseal Diamond type). I use the V33 Marine Hard Varnish.

3/ when that layer dries up and just becomes tacky, give it a second layer and let completely dry overnight.

4/ you can now fill up the wave with some more (multiple) layers of your chosen product or take the Freddie B-route. That’s my choice as it is lighter and sands amazingly well. You’ll find that ‘recipe’ by scrolling down on page 43 of my Ballerina build.

5/ then, have a last fine sanding getting it ready for your primer of choice.

Here is a test-piece for Bella’s wing in Depron with 25g/m² glass and a Fred B layer as above. I only went up to this stage as I covered my wing with vinyl adhesive. The second pic shows the same test-piece with a layer of primer added and ready for painting.

Hope this helps

Cheers

Chris

[Martin McIntosh]

The stuff I once tried was called Skin-Crylic, fine on simple curves but just not sticky enough to cope with compound ones so I abandoned the idea and went back to epoxy. Maybe the more recent products are rather better.

You may be better to use simple tissue and dope for things like the wing tips.

[Mark Elen]

Thanks Gents👍

Im probably going to have a little dabble with Fred's mixture Chris. I should have left that test piece to go off properly before I tried to pull the glass cloth off, it was still pretty 'green'

I've not got a whole lot done this week, although I have been out on my bike and done a load of miles. 32 yesterday.

What I have got done is the port aileron and flap and got all of the flappy bits sanded to profile and hinged up. I now just need to profile the leading edge and the tips, cut out the other servo holes and it's pretty much ready for the bandage and covering.

Cheers

Mark

[Mark Elen]

I've now reached a milestone in this build, in that I can't do a lot more with the wing until the fuselage is built, so today I bit the bullet and cleared the bench.

Followed by cutting up and laying out the fuselage plan and separating the fuselage bits from the laser cut sheets.

The laser cutting has left the edges not square, so I held them to the edge of the board and using the long sander resting on the front edge of the board, sanded them lightly till they were. This also took care of the 'toast'

I've got that lot all glued up and going off. No photo as my phone was flat.

The cutting is generally pretty good and accurate to the plan, although the side has ended up about a mm small just on the inverted v at the top. As long as the other side is the same, I'm not worrying.

I did make a start on covering the flaps the other night and tried filling the weave just using coats of the varnish just to see how it went. I'm up to coat five and it still needs some more.

I'm going to give in with that and mix up some of Freddie's Sauce to finish that off. Thanks for the recipe Chris! I went and got the filler today, along with a thick sheet of MDF to make up the SLEC fuselage jig that I got ages ago but have never got around to putting together. I'm pretty sure it's going to get used on this build.

As well as that lot, I managed to go flying today with both the Ballerina and the Viper, I'm really getting the hang of both of these now. I also got another 25 miles in on the bike.

All in all, a good day.

Cheers

Mark

[McG 6969]

Hi Mark,

Gaston and I insist on having a full test report regarding FredB's Sauce...

You'll see, it's dead easy to use, but don't make it too thick. 'Creamy'- like is the right consistency and better two thin coats than going too thick.

Good luck & Cheers

Chris