Moving large decals from the paper to the model

Only way I have found to move large decals is to use lots of water on the sheet and to touch the decal to the model then slide it into place by moving the paper along the route of the decal location.

I will have to give that another go.  The windows on the TOS Enterprise is causing the issue, very much a pain.

Sounds like you may have a sheet of bad decals.  Usually decals that are too old have the tearing apart problem.  If you are using decal set like Micro SET instead of water to soak them off the paper, that would make the problem even worse.

I recently had a set of decals that were ripping apart as I tried to slide them off the sheet.  I managed to work it out by letting the sheet soak in water an extra long time so that the decals were totally released and floating on a film of water, then I used a microbrush or toothpick to carefully push them off the sheet onto the model.  Even with that, there was some breakage, so I put the sections of decals on the model and carefully worked them into a properly matched position with a microbrush.  Then I let them air dry for many hours without blotting them.  After all the water had evaporated, I carefully put on a coat of Micro Sol with an eyedropper, again not touching them.  They were then fine after the Micro Sol did its job.

As a last step, I sealed them with Testor's Glosscoat.

I believe you can coat the decals with a layer of Future while they are still on the sheet. Once it cures, this will give the decal a bit of strength and should prevent tears. Just make sure you cut as close to the edge of the decal as you can when removing them from the sheet.

Pick up some Testors Decal Bonder and spray it over the decal sheet first. I believe the company that makes Micro-Set/Sol makes a similar product. Either way, it'll lend some extra durability to the decals so they won't tear or shatter as you move them.

I'd also recommend, where possible, to divide large decals into sections. It's not always feasible, but if you have parts that are just straight carrier film, you can cut there.

Thanks everyone.

The only time I had these issues with the decals is if I hadn't left them in the water long enough and/or the water got cold.  I usually start with warm water from the tap in glass bowl and place the bowl on a candle warmer, this keeps the water nice and warm.

After trimming the decals, I would place the decal in the water for at least 30 seconds, then removed it and let it sit for another 10 seconds, the decals release nicely...

I used a coat of Tamiya Pearl White Gloss as a base coat, applied aztec decals then gave it a coat of clear Pearl to tone down the Aztec before putting the other markings on...

For some especially large decals I will sometimes cut them into sections before putting them on the model. It is important to line up all the parts while all sections are still wet.

  I do the same as paintsniffer.  Those window decals are incredibly tricky just because of the way they're laid out.  I cut mine up into smaller bits and then went at it.  Takes a bit longer but you don't have to wrangle wayward decals that way.

Another  reason to transfer to the model while still on the backing paper, even with smaller decals, is to prevent an edge folding under.  With narrow decals, or ones with points/projections, it is hard to keep the decals, especially thin ones, from flopping around while transferring with tweezers.  This can lead to folds where the glue sides touch, and then you have to work to seperate the fold.  Putting the backing paper against the surface of the model and sliding the decal onto the model surface largely prevents that.