Solid balsa prow

Advert

New Replies

Report Bug

Help/FAQs

Solid balsa prow

This topic is empty.

Viewing 25 posts - 1 through 25 (of 33 total)

1 2 →

Author

Posts
25 March 2016 at 13:46 #2569
Steve Walker 1
Participant
@stevewalker1
Advert

25 March 2016 at 13:46 #64026
Steve Walker 1
Participant
@stevewalker1
I have looked for a thread re this but can't find one. I saw some plans for a boat with a solid balsa prow which is quite curved, ie like a PT boat. How do you shape it to get both sides the same, and how critical is this? would the keel make up for some difference? The plan is quite old but I have also seen plans for 'solid' yachts which would be even more critical in terms of symmetry.

Regards, Steve
25 March 2016 at 14:13 #64027
Paul T
Participant
@pault84577
Steve

It is critical to keep both sides of the bow the same otherwise your boat might make unexpected turns (depending upon the way you had sculpted the bow)

The best way to maintain uniformity is to make a series of progressive cardboard templates cut to the shape of the bow and use them to check your sculpting progress.

Good luck

Paul
25 March 2016 at 14:34 #64029
Dave Milbourn
Participant
@davemilbourn48782
Steve

There's a photo sequence of the building of my Huntsman's bow in my album **LINK**

Take only small amounts off each side alternately and check by eye – or with templates if necessary, as Paul says.

Dave M
25 March 2016 at 15:32 #64031
Dodgy Geezer 1
Participant
@dodgygeezer1
I tend to approach the problem by not having a solid prow. I gain uniformity by making identical formers running right up to the bow, and then skin the bow area with similar left and right skins. This shows up any slight imbalance, and lets me correct it if necessary.

I find that the bow can be subject to a fair bit of punishment, and that a carved block of balsa is usually quite soft and prone to dings. A made-up bow can have the grain all aligned for maximum strength.

Having said that, DM's example using a sandwich technique has a similar advantage – end-aligned wood and made in matching left-right pieces… and you should also be able to check that the glue lines are symmetrical…

Edited By Dodgy Geezer on 25/03/2016 15:37:14
26 March 2016 at 08:45 #64049
Steve Walker 1
Participant
@stevewalker1
Oh well, no old sea-dog quick fix then. Having looked at the pics I can see the secret might be to cut balsa so that it is symmetrical and only just big enough to shape the bow. That way you would only have to sand off the edges of the blocks. Maybe even make up a practice corner first to replicate one side of the bow.

I am already beginning to treat balsa dust with some respect. It's not very nice stuff!
26 March 2016 at 09:04 #64051
Bob Abell 2
Participant
@bobabell2
Sorry Steve…..We should have warned you about the dangers of inhaling balsa dust!

It's really dangerous stuff and it floats about in the air, ready to be inhaled!

You must wear a quality dust mask……..Not one of those flimsy face masks either!

I avoid Balsa for this very reason!

Bob
26 March 2016 at 09:22 #64052
Banjoman
Participant
@banjoman
Many hard- and softwood dusts can be more or less hazardous, and are best not inhaled if it can be avoided.

Obviously there's an important difference between the kind of exposure one is liable to be subect to as a professional woodworker compared to as a hobbyist, but personally I don't see the point in running an unnecessary risk when it can easily be avoided, and so always wear a pro quality half mask with an appropriate particle filter when working with wood.

For more facts about and a (non-exhaustive) list of toxic woods, see for example this HSE information sheet: **LINK** .

Again, this information is geared towards those subject to professional level risks of exposure, and so I dare say a few grains of salt may be applied for someone who is "just" building a few models, but still … it is better to know what's what, I think, and as far as reasonably feasible try to act accordingly.

/Mattias

Edited By Banjoman on 26/03/2016 09:22:51

Edited By Banjoman on 26/03/2016 09:23:04
26 March 2016 at 10:07 #64053
Dodgy Geezer 1
Participant
@dodgygeezer1
Posted by Banjoman on 26/03/2016 09:22:34:

………..

For more facts about and a (non-exhaustive) list of toxic woods, see for example this HSE information sheet: **LINK** .

Here's a specific MSDS on balsawood.

**LINK**

The two things that stand out to me are the low level of risk associated with balsa dust compared to other woods, and the small amounts of data which have been collected about it. To inform any discussion about 'Class 1 carcinogens' I append this item by Prof Lumley from a stats blog I follow:

**LINK**

..where you will see that other Class 1 carcinogens include sunlight….

I strongly support Banjoman's comment that 'it's better to know what's what…' . Would that we had the data to be able to do this…

Edited By Dodgy Geezer on 26/03/2016 10:09:52
26 March 2016 at 10:09 #64054
Dave Milbourn
Participant
@davemilbourn48782
I couldn't find balsa on the list, so I presume its side-effects are too mild to be of serious concern. I've been modelling with the stuff for over 50 years without any protection and aside from the odd sneeze I've never had any reaction to it. That said, I do most of my "bulk" sanding outside the workshop and let the breeze do the job of waste collection.

Filter masks are sensible when spraying paint or sanding fibreglass. As for Class 1 carcinogens, here's some terrifying information c/o The Daily Mail https://www.youtube.com/watch?v=q3chJN9DCGg

DM

Edited By Dave Milbourn on 26/03/2016 10:14:35
26 March 2016 at 10:14 #64055
Dodgy Geezer 1
Participant
@dodgygeezer1
Posted by Dave Milbourn on 26/03/2016 10:09:36:

…I do most of my "bulk" sanding outside the workshop and let the breeze do the job of waste collection….

DM

I suspect that the most hazardous impact of balsa dust is not covered in any MSDS, but relates to the impact your wife will have on you if she finds the dust in the soft furnishings and all over the dressing table….

Edited By Dodgy Geezer on 26/03/2016 10:17:05
26 March 2016 at 10:26 #64056
Dave Milbourn
Participant
@davemilbourn48782
I suspect that the most hazardous impact of balsa dust is not covered in any MSDS, but relates to the impact your wife will have on you if she finds the dust in the soft furnishings and all over the dressing table….

No soft furnishings or dressing table in my workshop, dude… …. and there's a 12" extractor fan in the wall at the opposite end.
26 March 2016 at 10:54 #64057
Colin Bishop
Moderator
@colinbishop34627
One thing that seems to be common to most of the woods on the list is breathing. So stop breathing and all your troubles are over!

There is no mention of infection being associated with teak yet in Nelson's time naval seaman didn't like serving in teak built ships (from India/Burma etc.) as the splinters caused by action damage were commonly regarded as causing infectious wounds.

Colin
26 March 2016 at 11:05 #64058
Steve Walker 1
Participant
@stevewalker1
I think if I get one more of 'the looks' from Mrs Walker, I may well stop breathing but it won't be voluntary! "It's only a bit of dust" wasn't greeted with a cheerie smile. And that was only my Tritons.

I think I had better work out where my long term working area is going to be.

I do love this forum though, in every conversation I learn something new that has almost nothing to do with boats!
26 March 2016 at 13:13 #64059
Dodgy Geezer 1
Participant
@dodgygeezer1
Posted by Steve Walker 1 on 26/03/2016 11:05:08:

…..

I do love this forum though, in every conversation I learn something new that has almost nothing to do with boats!

People come here to discuss model boats? I thought we were talking about Fat Tails:

Edited By Dodgy Geezer on 26/03/2016 13:14:13
26 March 2016 at 13:36 #64060
Steve Walker 1
Participant
@stevewalker1
Well I'm certainly not gaining from disorder. It might be the end of me in fact. Might call my next boat the black swan in honour of you.
26 March 2016 at 13:55 #64061
Dodgy Geezer 1
Participant
@dodgygeezer1
Posted by Steve Walker 1 on 26/03/2016 13:36:44:

Well I'm certainly not gaining from disorder. It might be the end of me in fact. Might call my next boat the black swan in honour of you.

Surely in honour of Nassim Taleb…?
26 March 2016 at 14:24 #64064
Dave Milbourn
Participant
@davemilbourn48782
Surely in honour of Nassim Taleb…?

Oi!! Referee!!!
26 March 2016 at 15:57 #64071
ChrisB
Participant
@chrisb29081
26 March 2016 at 16:53 #64074
Paul T
Participant
@pault84577
There is a pub near me called the Black Swan……how improbable is that?
26 March 2016 at 18:38 #64076
Dave Milbourn
Participant
@davemilbourn48782
Posted by Paul T on 26/03/2016 16:53:04:

There is a pub near me called the Black Swan……how improbable is that?

Should I care? If it bothers you then move.
26 March 2016 at 19:23 #64078
Paul T
Participant
@pault84577
It doesn't really bother me I was simply wondering what the odds were of being in close proximity of a pub called the Black Swan, I guess its about 600 to 1 so I had better hedge my bets.
27 March 2016 at 11:12 #64096
Dave Milbourn
Participant
@davemilbourn48782
Paul

It all depends on where you're standing at the time. In fact there were an estimated 48000 pubs in the UK in 2015, of which 59 are called the Black Swan, so you're not far off with 1/600 (it's actually 1/813).

Not a lot of people know that.

DM
27 March 2016 at 11:23 #64097
Kev.W
Participant
@kev-w
The closest pub to me is called the 'Black Swan', used to be my usual haunt until I found that the other local served 'real' ale, my loyalties now reside with 'The Barrel' (used to be the 'Green Barrel' but new owner, new name).
19 April 2016 at 16:13 #64758
Steve Walker 1
Participant
@stevewalker1
Once again apologies if I'm being a plonker.

I have put a trial solid balsa bow together and sanded it into shape. Only problem now is the glue is so much harder than the balsa and I'm getting a lovely display of razor sharp ridges. Do I sand further and rebuild with filler or do I use something other than fine sandpaper to deal with the glue, or something other than the Evo-stick I am using.

It's not a big deal and I will work around it but I thought I would just romp through both and then cover with some ezekote. It's not working out like that and I'm just wondering if there is a better way to avoid double work.

Regards, Steve
Author

Posts