Tip with Foam or Bristle brush

[Finallybuyingaboat]

I just finished applying 3 coats of primer. I tipped out the last two coats fo practice for when I hit the actual painting. However, using the natural bristle brush, I did end up with quite a few brush marks. It was cold and I probably should have added more thinner to help out the flowing process. I may also have not held the brush at a steep enough angle to the primer and a long portion may have been dragging through the paint.

There are many people who claim to use foam brushes to tip off a paint job according to the research I have done on the web .Do these work? What angle should you hold the brush since the tip of the foam brush is already angled 45 degreees?

[JohnRPollard]

I've had better results tipping with a foam brush.

If you have a helper who can follow along and tip right behind you it goes more quickly. But doing it solo is not that hard either. Always keep a wet edge and tip back towards the new paint.

[artbyjody]

I prefer bristle brushes. Foam has a tendency to push paint along - bristles have a little flexibility. Use a foam / epoxy rated roller to do the initial base application - follow through with a bristle brush at a 45-55 degree angle - wipe off the brush as it gets excess - rinse in acetone as well - wipe off with rag well. Work in no more than 2 foot lengths as any 2 part primer is difficult to work with as there is no real lag time. If the roller or brush sticks instead of being fluid over it - it has already set and your work will entail alot more sanding between coats...


To get a uniform coating alternate between horizontal and vertical brush strokes on each layer. Meaning first primer coat - go vertical starting top to bottom - roller and brush. Sand, rinse then do the roller application vertical but do the brush strokes horizontal starting left to right. I always wet sand with a fine grit between coats, clean with acetone before next application.

Depending on if this is a bottom job or a paint job - if painting the hull / deck - cut the primer 3 to 1 with whatever color you intend to paint after the primer. This will reduce the number of layers you have to apply - especially if painting a darker or more vibrant color. If just primer for application of bottom paint that is not really an issue.

[pdqaltair]

Originally Posted by Finallybuyingaboat

I just finished applying 3 coats of primer. I tipped out the last two coats fo practice for when I hit the actual painting. However, using the natural bristle brush, I did end up with quite a few brush marks. It was cold and I probably should have added more thinner to help out the flowing process. I may also have not held the brush at a steep enough angle to the primer and a long portion may have been dragging through the paint.

There are many people who claim to use foam brushes to tip off a paint job according to the research I have done on the web .Do these work? What angle should you hold the brush since the tip of the foam brush is already angled 45 degreees?

Man wants to have his way, but...

Second using a fine bristle. Best you can find, and clean and store it carefully. Foam doesn't manage curves as well. It is worth it. Get cheaper ones for utility painting.

[Gary M]

I agree that a good bristle brush works best. A badger hair brush works very well. What paint are you using? I used Awlgrip last year for the first time and it is by far the nicest paint I have ever applied.

I did check the surface temp to make sure it was between about 70 and 90 degrees and painted on a sunny day.

Good Luck
Gary

[US27inKS]

I used a brush that I got at the local hobby store (Hobby Lobby). Actually I used a bunch of them. I found a set of 3 chip brush style brushes that had high quality very fine nylon bristles instead of the usual course bristles you get at the hardware store. The 3 pack was 3 dollars. I didn't use the narrower 2 brushes, and just tossed them. At 3 bucks each, it was cheaper to toss the brush after each use than clean it with interlux 2333. I got a better shine from this brush than from the badger or china brushes that I paid more than 20 bucks each.

I tried a foam brush. Interlux perfection eats foam brushes in a matter of minutes.

[Finallybuyingaboat]

I am wondering if I can use an orbital sander for the last sanding of the primer or should I just hand sand? Going to go with 240 and then 320.

[tommays]

The primer hand sands very fast a random orbit woul take off far to much material

You just need to sand with one grit something in the 200 grit range will be fine as your looking to knock down high spots as well as provide a surface that will allow the topcoat to GRIP


The finer grits will work when your sanding between finish coats

[US27inKS]

It really depends on what kind of primer you use. Interlux's epoxy primer is pretty tough stuff. To get the very best finish, you need to hand sand it with a sanding block. Wet sanding is even better, but you need to go with the next grade finer paper. Put just a few drops of dish soap in your water bucket and use a 3M wet sanding squeegee to see when you have the surface perfect. Make sure you use a sanding block, otherwise you'll have a wavy boat.

Originally Posted by Finallybuyingaboat

I am wondering if I can use an orbital sander for the last sanding of the primer or should I just hand sand? Going to go with 240 and then 320.

[poopdeckpappy]

I'm gonna go against the gain here, I use cheap Natural bristle brushes even on the varnish, I take a couple mins to groom and trim the bristle if needed, ( this gets rid of any the wild ones ) then wrap a band of masking tape around the brush where the bristle and handle join ( this keeps any bristle from coming off ). You can buy these is bulk cheaper than some high dollar brush and you can toss them after each session, using a new one on the next.

Look at it like digital photography, with very little extra effort. you can get the same picture out of a 300 dollar point & shoot as you can out of a 3000 dollar DSLR, mega pix are mega pix, bristle are bristle, all things being equal the results will be the same, who cares if the bristle are set in a piece of unfinished bandsawed pine or a piece of machined and highly lacquered maple with a epoxy white racing stripe