Fairing and prep questions.

[OldSkool67]

So I have started the sanding process on the exterior of the boat. It was in pretty bad shape, two different topside paint jobs over the gelcoat with lots of peeling and cracking. It appears there will need to be a lot of fairing. I have no experience with doing any type of fairing on boats. I have painted a few boats and cars in the past but never taken on something that will needed as much attention as this.

fairing material, is there a big difference between the different products?
I have several cans of 3m bondo from other projects, can this be used?
Im not sure what is going to show after its primed and painted, if I prime the boat and find areas that need additional work can you use the fairing over the primer?


If you have any other tips or recommendations please let me know.

[gran398]

Good looking flatback!

We are fortunate to have excellent, experienced P and F guys here. They'll advise you as to stripping, prep, and compatibility.

Keep us posted

[Capt Matt]

Once you get some primer on you will have a much better idea of where you are at. I bought cheap rattle cans of primer at the local hardware store to spray problem area's so when I did finally spray with 545 there was not close to as much to fair.
Capt Matt

[OldSkool67]

Thanks

Good looking flatback!

We are fortunate to have excellent, experienced P and F guys here. They'll advise you as to stripping, prep, and compatibility.

Keep us posted

Thanks gran398, I get more excited everyday about this project.

Capt Matt, I had some cans in the garage so I went out and hit a couple test spots... I was suprised how much doesnt show when its primed. I imagine when I use a high build primer it will be even better.

[gran398]

Absolutely! Glad you're excited.

Nothing better than a new rebuild...and the good news...you have a flatback.

Exciting new pics today of a rebuilt flatback from the past...she's deluxe, and as shown in the pics, a multipurpose platform

The main thing you'll deal with...paint compatibility over the old substrate. Check for incompatibility/orange peel. Feel certain our master rebuilders will address this.  Time on the longboard is time well spent.

Thanks...keep us posted!

[bondobill]

Oldskoll

Something to think about.
Putting fresh paint over old, the new paint will only hold up as well as the old finish under it.
You said you have 2 old topcoats and they are cracking and peeling. Trying to sand off all the bad spots is tough to get them all.
Putting primer over any spots you missed will come back to haunt the new paint later.
 Been there done that !
I would suggest sanding all the old paint down to the gel.
It will be more work removing it, but will save you a lot of time in the priming and sanding.

Just a thought
Good Luck

Bill

[dirtwheelsfl]

exactly what bill said. just do it once and take it all the way down to gel, then buildup from there. youll also find any imperfections in the gel hidden under the paint that you dont want to pop up later.

as far as products, stay away from the bondo. duraglass is acceptable above the waterline but only in very small applications like a gouge or pinholes and such. then 3m makes their vinylester fillers which are better than the polyester bondo based. but for my money, everything is going to be epoxy. ive seen too many cases of other fillers shrinking and cracking whats layed on top of them. interlux "watertite" is great for small areas, which is all i anticipate on your hull because it looks pretty good to start with. also anything you fill after your primer, will be epoxy on epoxy rather than something else trying to stick to the primer.

if youve got large areas to do, you can buy pre-thickened epoxy mixtures, or you can get a small kit of 2:1 and blend your own with fillers. a big drywall blade is a necessity for applying also. there are a ton of ways to do it, google search will probably yield some results...

[Capt Matt]

Mine was still original gel coat so I did not have to worry about getting rid of the old paint. The bottom I had sandblasted and spent weeks filling pin holes
Looking good
Capt Matt

[kraw2]

Use the rattle can primer in grey like Capt. Matt has said. I would recommend West Systems Epoxy with their fairing filler when it comes time to straighten everything out. Easy to use, waterproof, ect..

Your doing a great job already. All the work is in what you are now doing so I wouldn't skimp on cheap paint when it's ready.

[Group W Bench]

Skip the rattle can paint. Use blue tooling dye and thin it it around 10:1 with denatured alcohol. Dychem is probably the most common brand. Wipe the entire hull with the blue solution and start sanding. The low spots will stand out in blue. You can fair directly over the top and not worry about adhesion issues that you will with rattlecan paint or primer.

[RickK]

New method  
Where can we get that stuff Eugene?

[kraw2]

This is what the hull will look like after filling and using the guide coat to find high and low spots.

[OldSkool67]

well I have been logging in some sanding hours thats for sure. The two top coats are gone but Im having tough time figuring out what im still dealing with, the gel coast is an off white, but im finding pockets of a very tan paint or fairing material.

Here are some updated pics.