I bought some decals for my AlAn project and am a bit nervous to try and apply the down tube decals, only one shot. Can anyone give me ideas, tips as to how I get them on straight and w/o bubbles and basically without messing it up or things to avoid when doing this? I have never done decals on a bicycle before, thanks.

What kind? Vinyl type from Cyclomondo, etc?

If so, yes, you get one shot at it, but if you use the "wet method" you get a bit of time to slide the decals into position.
Dampen the frame after cleaning it well and place the decals onto the wet frame and "squeegee" the water out from under the decal with a paper towel.

As for alignment, cut some very thin strips of blue masking tape, 1/8 inch or so, and place them on the frame tube to act as alignment guides. Same place both sides. If they don't look right, remove and re-place them. Place them just outside where the decal will sit. A long, thin line of tape will help the eye see if the decal is straight.

It helps also to run one thin strip of tape right down the top of the down tube, centered on the head tube lug point.

Yes cyclomondo and excellent tips rootboy, many thanks.

It's a bit of a white knuckle experience. I know it was for me. But if you've got everything laid out, ready to go, and sort of do a dry run or two before you start, it helps. Once you lay the decals onto the wet frame, you've only got about 3 or 5 seconds to get them into position, and having little strips of tape really helps. Work quickly and with confidence. It's not too bad. Good luck.

I use a drop or two of liquid soap in the application water and i've never had a problem repositioning the decals, even to the point of completely removing and repositioning them. Don't be afraid to use lots of water on the frame any excess will press out. I generally use my thumbs for the initial "squeegee" then a soft cloth to soak up the excess water. Greg Softley recommends at least a week before applying clearcoat to let any trapped moisture evaporate. Good luck!

JR at Velocals recommended the soap technique, too. I think it helped a little. With a tall seat tube wrap, it's just a stressful deal because there's so much surface area, I think. On the Trek frame below, I added to the degree of difficulty by adding a second set of water bosses to the frame, so I had to punch a hole in the decal, get that in the right place, and still center the decal itself. Came out well enough, but wouldn't want to do it again, thank you very much! I agree with rootboy, lay it out with tape.

Water with a bit of soap method, tape also. Measure, measure, and measure again. Once you're satified with the placement, squeeze out the water, I used a regular business card, instead of a plastic style "squeegee". The plastic would tend to "grab" the decal too much.
Decals by Velocals.

+1 on the drop of soap technique. That'll give you as much time as you need get the decal straight before you squeegee the water out and dab it dry.

Another good tip is to make sure the downtube decal is positioned slightly higher than the middle of the tube, so it will appear centered when viewed from above. I didn't explain that very well, but look at the first photo of Michael Angelo's beautiful Paramount above, and you'll see what I mean.

Yes, and I'll add this even if it might seem overly anal. I was a little worried about that sharp edge on the the credit card, so I took some 200-grit and "rounded it over" a bit. The velocals decals are pretty thick, but discretion being the better part and all...

Another tip I used is to seal the edges of the decals/stickers with an edge sealing pen used by sign makers. Works great. If you plan to clear coat the whole thing though, disregard this step.

Rootboy, I hadn't considered clear coating the frame. As it is now, I have the original seat tube decals in battered shape, but I like keeping some of the original decals in tact to help show the way the bike was 32 years ago and also how well they held up. I am planning on just applying new down tube decals because someone suggested the frame looks unbalanced without the down tube decals and I do agree after looking at it. I had never heard of an edge sealing pen. I like that, thanks. I am off work today so I may lay out the decals this afternoon. I will also try some soap when I actually apply the decals. Great tips from everyone, thanks.

The trek and paramount look fantastic by the way.

This is the one I used:
https://www.rvinyl.com/application/to...m#.UQ6elqVj65Q

I just ordered one, thanks for the link.

There is a considerable difference in size from the original.

Would have never thought of that, thanks.

Space them to the correct distance and they will look great.

I thought it was just one piece and I don't think I am steady enough to cut this into fourths and evenly space then horizontally and vertically.

Well I applied the AlAn decals on the down tube last night. It wasn't an easy start because with water and a bit of soap I couldn't get the decals to even stay in place. Once I wiped of the water the decals did stick and I was able to get them in place. I did have to pull them to re stick and ended up with one of the A's having a very slight crease (blah!). Over all it was pretty smooth and I will know what to expect next time I do this. I would like to that the few that responded with tips to help with the learning process. Now if I can ever get the replacement cup to show up I can finish the assembly.

Good for you, man. Experience is the best teacher, esp. where decals are concerned. Best of luck with the rest of your build!