Heatgun, danger to fiberglass ?

[Sven]

Most of our brightwork needs to be stripped and refinished. We've varnished the bare spots as a stopgap to prevent more damage but that is only a temporary solution and doesn't look too good.

I have never used a heat gun for paint or varnish stripping but having read up on the topic it seems like the only way to go.

- I asked the marina/yard operator if sanding in the slip was ok and he said that hand sanding was fine but power sanding would produce too much dust and the yard might get in trouble. The yard/marina are outstanding so we will not do anything which might cause them trouble. I'll only use hand sanding for the final stripping and touch-up.

- Chemical strippers are too nasty and there is too much wood to strip. I might use it in the hard to scrape areas but not for the larger ones.

So, reading about how easy heat-gun stripping is I wonder what kind of damage it might do to surrounding FG or the gel coat ? 500-1000+ degrees F is pretty hot

Likewise, I wonder what the damage mitigation strategies might be ? Do you use a metal plate or something else to shield the nearby FG from the direct blast of heat or do you just stay away from the varnished areas that abut FG ?

Insights will be appreciated, as usual,


-Sven

 

[Loren Beach]

Your basic hand-held heat gun is small enough that you will be putting the flow of heat on the varnish and not the glass, IMHO.
I have used one many times for less intensive tasks around the boat, like removing the old registration stickers before applying the new ones. I also use it for softening sealant to remove fittings -- makes the metal too hot to touch.


As to sanding, I would save that for finish prep, and then do as the more progressive yards have done for a decade around here -- use a Fein dustless vac with the hose connected to the sander. No mess, air stays clean, and you can tack off and varnish minutes later. We have the smallest Fein vac and have done exactly that for a variety of varnish projects. Once you try vacuum sanding, you never go back.

For dealing with big surfaces, how 'bout reconsidering using a chemical stripper for the bulk of the work? Maybe?

best,
Loren

 

[Martin King]

Sven,
If an adjacent surface next to what you are stripping happens
to be gelcoat or painted, I will go to the extra trouble to mask
it off. I use a sharpened scraper with the heat gun and one
little slip can cause a nasty scratch. Some pros will even
lay down a double layer of tape. If you've never used a heat
gun before, get in the habit of moving the nozzle off the work
after short bursts until you can accurately judge your distance
and time to lift the finish.The ideal is to just melt it off without
producing blisters.

Martin

 

[mherrcat]

I used a heat gun for just this purpose on my cabin top hand rails a couple of months ago. It works very well with a sharp scraper, but as Martin mentioned, be very careful not to slip. (It was tricky getting the underside of the rail between the mounting points.) Masking will help, but a sharp scraper can cut through a couple of layers of paper tape very easily. If you use a file to keep the scraper sharp you don't have to use very much pressure to remove the varnish.

This is the fastest an neatest way to do it in my opinion. Sanding down several layers of varnish to bare wood would be a real PITA!

I used the gun on the low setting and was careful to keep it moving over the surface of the wood until the varnish just started to blister. You'll see it easily when the varnish starts to soften. The scraper then takes it off completely. Then just use some teak cleaner and sand smooth and you're ready to re-coat. I didn't use any kind of stain on the wood prior to varnishing.

 

[treilley]

I have seen heat guns discolor gelcoat very quickly. I would use something to shield the gelcoat from the heat that may get deflected onto it. A very wide spackling knife comes to mind.

I have also seen gelcoat burns on topsides from inexperienced marina monkeys installing shrink wrap.

 

[Martin King]

I have also seen gelcoat burns on topsides from inexperienced marina monkeys installing shrink wrap.

This reminds me of something else I wanted to mention. Before
picking up a heat gun, you need to be in the right frame of mind.
You need to be totally focused on the job, or you will cause
expensive damage. All it takes is a couple of seconds of distraction
and you will have fried gelcoat or burnt wood or both. Treat that
gun with the respect you would show any power tool and it will serve
you well. Get cocky around it and it will bite back hard.

 

[u079721]

Stupid (or rather obvious) observation - but all heat guns are not the same. I have one from work that is so powerful that it will catch paper on fire in no time. That one I would never take any where near the boat. But I have another with variable heat and a removable nozzle tip that I have used frequently to remove old decals and such. I always start out at low settings and only increase the temp dial to where I see the softening I want. Never start out on high.

 

[mherrcat]

One other thing I forgot to mention; the work area is very small, only a couple of inches at a time. Even so, because the varnish will come off so easily, the work goes pretty quickly.

 

[dcoyle]

I used an environmentally freindly product on bottom strip job which also works on wood finishes. Product called Soy Strip, available at West Marine or cheaper on line. Stuff is water soluble(spell check- fri nite) and biodegradable, and easy on your body. The distributor in New England is a fellow called Captain John and is good guy for information. May work for your situation. A freind used it to remove finish on Sabre 34 cabin sole and was very happy with results.

 

[CaptDan]

For dealing with big surfaces, how 'bout reconsidering using a chemical stripper for the bulk of the work? Maybe?

best,
Loren

Last year when I stripped (again) my coamings and handrails, I used that scraper-friendly orange/citrus stripper from Home Despot(tm). It was just as effective as that Jasco A-Bomb stuff, without the unpleasant side effects.

Just a thought.

Capt Dan G>E35II "Kunu"

 

[Sven]

Thanks for all the answers and shared experiences !

Time to get a heat gun and spend some of the two holiday weeks stripping ... if the weather holds.



-Sven

 

[Glyn Judson]

Heat gun.

Sven, I have a pretty cool heat gun you can borrow if you wish. It has two fan speeds and an infinitely variable thermostat control. If interested, contact me back channel at glynjudson@roadrunner.com or by phone at 310.453.1892 Glyn

 

[Sven]

Glyn,

Sven, I have a pretty cool heat gun you can borrow if you wish. It has two fan speeds and an infinitely variable thermostat control. If interested, contact me back channel at glynjudson@roadrunner.com or by phone at 310.453.1892 Glyn

Thanks Glyn. That's very generous, as usual !

Which one is it, in case I don't make it to the Santa Monica area but try to find one down in San Diego or back home in Altadena. I assume you have been happy with it ?

We did get one quote for stripping and putting on 8 coats and it came out to $2-3K which isn't in the budget with the standing rigging replacement in January. It would be a lot easier to have Miguel do the work but I doubt he'd want to commute to San Diego

Hope you and Marilyn and the pups are having a good time.


-Sven

 

[Glyn Judson]

Heat gun type.

Sven, It's a Master Appliance Corp. Model 1500 that looks just like this Model 1000 currently on eBay: 220219214879. I have to assume that the 1500 makes reference to the maximum wattage but strangely enough, it says nothing to that effect elsewhere on the gun. It draws 9.0 amps max. with a temperature range of 150 F (65C)-650 F (345 C) and is yours to use should you choose to do so. Marilyn and the pups are fine. Glyn

 

[Emerald]

This may sound nuts, but why not a hair dryer? These things are often 1200-1500 watts. Is it the duty cycle? If you're working on and off heating and scraping, is it really an issue anyway? Thinking that if you are worried about over heating, this might be a conservative approach and you might have one on-hand.

 

[Sven]

Success ... wonderful tool !

For dealing with big surfaces, how 'bout reconsidering using a chemical stripper for the bulk of the work? Maybe?

best,
Loren

Hi Loren, after trying both I'm not sure chemicals are any faster. I'm hooked (if you can be hooked on a chore).

Sven,
If an adjacent surface next to what you are stripping happens
to be gelcoat or painted, I will go to the extra trouble to mask
it off.

Martin,

I did manage to scorch some tape but none of the gel coat

(It was tricky getting the underside of the rail between the mounting points.)

I now know what you are talking about. I also think that shaped scrapers might help.

you need to be in the right frame of mind.
You need to be totally focused on the job, or you will cause
expensive damage

Yup, there were two of us (Nancy and I) so we could keep watch. We both caught each other too intent on some particular spot to realize that the gun was still pointing at something else.

Stupid (or rather obvious) observation - but all heat guns are not the same

Santa brought a variable power gun but in retrospect I think I would get a "single high heat" gun and just use distance as the controller. The different nozzles sure help too !

One other thing I forgot to mention; the work area is very small, only a couple of inches at a time. Even so, because the varnish will come off so easily, the work goes pretty quickly.

I agree, I was amazed to find that I could slowly strip a blade-width for the full length of the wood by controlling the speed and running the gun just ahead if the blade.

I used an environmentally freindly product on bottom strip job which also works on wood finishes. Product called Soy Strip

Thanks for the suggestion, we'll keep that in the suggestion box.

Last year when I stripped (again) my coamings and handrails, I used that scraper-friendly orange/citrus stripper from Home Despot(tm).

The chemical solutions might still be the best solution for hard to heat places so that is another suggestion we'll keep in the stack.

Sven, I have a pretty cool heat gun you can borrow if you wish.

Thanks Glyn, santa brought me a "Milwaukee 8985 Variable Temperature Heat Gun Kit, 11.6 Amp, 140 to 1040 Degree Fahrenheit Kit" which is wonderful. Given the quote we were given for some of our brightwork I think it has already paid for itself in just one afternoon. We may soon be back up in MDR (the Boat Yard) and you are most welcome to borrow it if you get tired of yours.

This may sound nuts, but why not a hair dryer? These things are often 1200-1500 watts. Is it the duty cycle? If you're working on and off heating and scraping, is it really an issue anyway? Thinking that if you are worried about over heating, this might be a conservative approach and you might have one on-hand.

It might be the rating of over 10 amps at 110 volts. I think that is almost 10 times the heat of a hair dryer. The reverse might be a possibility but might result in frizzies ?


All in all, a wonderful tool !

Thanks for all the suggestions and comments !!


-Sven