I'm working on covering my wing for a 4*60 and need advice about using Ultracote over Ultracote for some trim pieces. I'll be putting a 4"x10" piece of trim over a covered wing bay. Should I use a pin or "woodpecker tool" to perforated the base covering before ironing on the trim piece, even though the base covering has no support in places (it spans between the ribs)? Thanks for the advice.

In your instance I suggest 1 of 2 things:

1. Due to the size of the trim piece, use Monokote and apply it using the windex method. AFTER IT HAS DRIED (24 -48 hours) iron all your edges with a trim iron or seal them with clear nail polish.

2. Use the Ultracote, but start in the middle of the trim piece and iron towards the edges. Keep tension on the piece while ironing. You should be able to attach it with few (if any) bubbles. Any bubbles you may get, ***** them with a pin and iron the bubble towards the pinhole to get rid of the trapped air.

The woodpecker is not necessary, especially over open areas.

I've placed UC over UC before using Campy's suggested method and it's worked well. I would however, use the woodpecker on the area you intend to cover as insurance if I had one on a larger piece such as you suggest. Make sure the base layer you are placing UC over is fully shrunk.

somegeek

I've used UC over UC several times but always end up with a small bubble or two before I'm done. I'm not a perfectionist so I think they came out pretty good. Better than many ARFs I've seen. I apply the trim with minimal heat to avoid shrinking/warping the trim and go back over it several times later to keep it from coming up. The trim just seems to stick better for me after several heat cycles. Keep a stick pin handy to pop any bubbles that come up. Put the iron on them to get the air out and then immediately place a cool, wet wash cloth over the bubble firmly to stick it down. In the future, on models that I'm more particular about, I'll use the moneykote/windex method as mentioned by Campy.

I use Uc over Uc all the time with little to no problems. Make sure the Base layer is fully shrunk. then I use the woodpecker.
Yes you can use it between the ribs with no problems.

It is critical that you watch your heat when applying ultracote trim. Unless you iron very uniformly with a steady medium level of heat you will draw in a straight edge and make it curve. Ultracote is very sensitive whereas Monokote is stable........but very bubbly.

I've experienced the curving straight line effect and redone quite a few pieces to fix it. Try using a wet paper towel along the straight edge of the ultracote trim as you iron it down. This keeps the edge cool and less likely to shrink. Also, one advantage of ultracote is that you can heat it up again and pull it off if you don't like your first try. Monokote doesn't allow that.

Good points!

Great tip!

I used the monokote windex method in the last few days to apply MK graphics... good stuff.

somegeek

I used Ultracote for base and trim.
Pic 1: finished bottom - the base is red with white and yellow trim - no perforations. Trim applied with a very low heat, socked iron moving, very very slowly from one end to the other. Same technique used for both wing and tail feathers. No bubbles.
Pic 2: finished top - base is red with white and yellow trim - sharpened T-pin used to perforate under all trim. Trim pieces were cut and laid out as stencil and outlined with sharpie fine point as boundary for perforations. Trim applied with a very low heat, socked iron moving very very very slow ly from trim points to broad ends. No bubbles.
Pic 3: finished side view
Pic 4: finished tail feathers - base red yedda yedda yedda - no perforations. Trim applied with a very low heat, socked iron moving, very very slowly from one end to the other. Same technique used for both wing and tail feathers. No bubbles.
Pic 5: finished side - yellow base laid down, then red base overlapping yellow, then white trim applied - no perforations. Same technique. No bubbles.
Pic 6 thru pic 8: application of white trim over red

I had to remove-replace several pieces because I moved the iron too fast resulting in captured bubbles irrespective of perforations used / not used. I can't over emphasize that the iron needs to be moved ever so slowly.

My favorite LHS owner (one of our best builders) looked hard and long for bubbles - he commented that this is one of the most "bubble-free" coverings that he had ever seen. The above technique must work.

I also played with Monokote Trim Solvent to prep the Ultracote adhesive. Did it ever!!! Too much for a rookie like me - you need to get it exactly on the mark. It sure did a great job as a heatless method - and fast. Seems that if you had a way to lay a trim piece adhesive side up with one end applied to the base and THEN be able to roll the trim on with a the flat side of your hand or dowel or one of those pet hair removing roller with a handle on the side ... emmmmm, where's that pet smart store ...

This RC stuff is way to much fun ...

"edit comment: can't count sorry"

carsondoc - did you ask me why I broke up the red bottom base into 3 pieces? (my memory is failing way too quickly). The reinforcing fiberglass tape wasn't even and I was concerned that if I simply overlapped two pieces on top of the tape seam that they would not seal properly. So, I spanned both sides of the tape with a single piece of covering first. Then I covered from this center strip to the tips. The adhesion between two pieces of covering is much stronger than between the covering and construction material.

hth,